Note: This page contains sample records for the topic unique genetic markers from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Genetic Markers Unique to Listeria monocytogenes Serotype 4b Differentiate Epidemic Clone II (Hot Dog Outbreak Strains) from Other Lineages  

PubMed Central

A small number of closely related strains of Listeria monocytogenes serotype 4b, designated epidemic clone I (ECI), have been implicated in numerous outbreaks of food-borne listeriosis described during the past two decades in Europe and North America. In 1998 to 1999, a multistate outbreak traced to contaminated hot dogs involved a different strain type of serotype 4b, with genetic fingerprints rarely encountered before. In spite of the profound economic and public health impact of this outbreak, the implicated bacteria (designated epidemic clone II [ECII]) have remained poorly characterized genetically, and nucleotide sequences specific for these strains have not been reported. Using genome sequence information, PCR, and Southern blots, we identified DNA fragments which appeared to be either absent or markedly divergent in the hot dog outbreak strains but conserved among other serotype 4b strains. PCR with primers derived from these fragments as well as Southern blots with the amplicons as probes readily differentiated ECII from other serotype 4b strains. The serotype 4b-specific region harboring these fragments was adjacent to inlA, which encodes a well-characterized virulence determinant. The findings suggest that ECII strains have undergone divergence in portions of a serotype-specific region that is conserved in other serotype 4b strains. Although the mechanisms that drive this divergence remain to be identified, DNA-based tools from this region can facilitate the detection and further characterization of strains belonging to this lineage.

Evans, Matthew R.; Swaminathan, Bala; Graves, Lewis M.; Altermann, Eric; Klaenhammer, Todd R.; Fink, Ryan C.; Kernodle, Sheri; Kathariou, Sophia

2004-01-01

2

Genetic Marker for Endocrine Disorders.  

National Technical Information Service (NTIS)

A genetic marker associated with polycystic ovary syndrome is disclosed. The presence or absence of the allele is highly predictive of whether an individual is at risk from polycystic ovary syndrome. Methods of diagnosis, markers, and primers are disclose...

A. E. Dunaif

2003-01-01

3

Genetic Markers in Plant Evolutionary Ecology  

Microsoft Academic Search

Genetic markers have provided plant ecologists with a method of assessing levels of genetic relatedness among individuals and populations. In recent years a number of techniques based on DNA sequence variation have been developed to complement allo- zyme methods that are already widely used. Some of these new markers are more variable than protein-based markers, allowing more precise estimates of

Mitchell B. Cruzan

1998-01-01

4

RJPrimers: unique transposable element insertion junction discovery and PCR primer design for marker development  

PubMed Central

Transposable elements (TE) exist in the genomes of nearly all eukaryotes. TE mobilization through ‘cut-and-paste’ or ‘copy-and-paste’ mechanisms causes their insertions into other repetitive sequences, gene loci and other DNA. An insertion of a TE commonly creates a unique TE junction in the genome. TE junctions are also randomly distributed along chromosomes and therefore useful for genome-wide marker development. Several TE-based marker systems have been developed and applied to genetic diversity assays, and to genetic and physical mapping. A software tool ‘RJPrimers’ reported here allows for accurate identification of unique repeat junctions using BLASTN against annotated repeat databases and a repeat junction finding algorithm, and then for fully automated high-throughput repeat junction-based primer design using Primer3 and BatchPrimer3. The software was tested using the rice genome and genomic sequences of Aegilops tauschii. Over 90% of repeat junction primers designed by RJPrimers were unique. At least one RJM marker per 10 Kb sequence of A. tauschii was expected with an estimate of over 0.45 million such markers in a genome of 4.02 Gb, providing an almost unlimited source of molecular markers for mapping large and complex genomes. A web-based server and a command line-based pipeline for RJPrimers are both available at http://wheat.pw.usda.gov/demos/RJPrimers/.

You, Frank M.; Wanjugi, Humphrey; Huo, Naxin; Lazo, Gerard R.; Luo, Ming-Cheng; Anderson, Olin D.; Dvorak, Jan; Gu, Yong Q.

2010-01-01

5

Molecular Marker Discovery and Genetic Map Visualisation  

Microsoft Academic Search

\\u000a The bulk of variation at the nucleotide level is often not visible at the phenotypic level. However, this variation can be\\u000a exploited using molecular genetic marker systems. Molecular genetic markers represent one of the most powerful tools for genome\\u000a analysis and permit the association of heritable traits with underlying genomic variation. Molecular marker technology has\\u000a developed rapidly over the last

Chris Duran; David Edwards; Jacqueline Batley

6

Molecular Marker Systems for Oenothera Genetics  

PubMed Central

The genus Oenothera has an outstanding scientific tradition. It has been a model for studying aspects of chromosome evolution and speciation, including the impact of plastid nuclear co-evolution. A large collection of strains analyzed during a century of experimental work and unique genetic possibilities allow the exchange of genetically definable plastids, individual or multiple chromosomes, and/or entire haploid genomes (Renner complexes) between species. However, molecular genetic approaches for the genus are largely lacking. In this study, we describe the development of efficient PCR-based marker systems for both the nuclear genome and the plastome. They allow distinguishing individual chromosomes, Renner complexes, plastomes, and subplastomes. We demonstrate their application by monitoring interspecific exchanges of genomes, chromosome pairs, and/or plastids during crossing programs, e.g., to produce plastome–genome incompatible hybrids. Using an appropriate partial permanent translocation heterozygous hybrid, linkage group 7 of the molecular map could be assigned to chromosome 9·8 of the classical Oenothera map. Finally, we provide the first direct molecular evidence that homologous recombination and free segregation of chromosomes in permanent translocation heterozygous strains is suppressed.

Rauwolf, Uwe; Golczyk, Hieronim; Meurer, Jorg; Herrmann, Reinhold G.; Greiner, Stephan

2008-01-01

7

DNA marker technologies and their applications in aquaculture genetics  

Microsoft Academic Search

The development of DNA-based genetic markers has had a revolutionary impact on animal genetics. With DNA markers, it is theoretically possible to observe and exploit genetic variation in the entire genome. Popular genetic markers in the aquaculture community include allozymes, mitochondrial DNA, RFLP, RAPD, AFLP, microsatellite, SNP, and EST markers. The application of DNA markers has allowed rapid progress in

Z. J. Liu; J. F. Cordes

2004-01-01

8

Genetic Screening: A Unique Game of Survival  

ERIC Educational Resources Information Center

|A creative learning game that helps students reinforce basic genetic information and facilitate the identification and understanding of the more subtle issues is presented. The basic framework of the game was conceived by a business major taking non-biology major course 'heredity and society-intertwining legacy.|

Kurvink, Karen; Bowser, Jessica

2004-01-01

9

Genetic Screening: A Unique Game of Survival  

ERIC Educational Resources Information Center

A creative learning game that helps students reinforce basic genetic information and facilitate the identification and understanding of the more subtle issues is presented. The basic framework of the game was conceived by a business major taking non-biology major course 'heredity and society-intertwining legacy.

Kurvink, Karen; Bowser, Jessica

2004-01-01

10

Update on genetic markers for pork quality  

Technology Transfer Automated Retrieval System (TEKTRAN)

To determine the robustness of reported marker associations with pork quality traits, assay systems were developed for as many polymorphisms from the literature as possible. These assays were genotyped across pigs (n = 1,291) with pork quality data available from four populations. Genetic marker-phe...

11

Genetic Markers in Cardiovascular Disease  

Microsoft Academic Search

\\u000a For classic “Mendelian” genetic diseases, a single gene is responsible. A rare mutation in that gene causes a dramatic change\\u000a in protein concentration or function that is both necessary and sufficient to cause the disease, and environmental factors\\u000a play a small or nonexistent role. Examples in cardiology include familial hypercholesterolemia, familial hypertrophic cardiomyopathy,\\u000a Marfan syndrome, and congenital long QT syndrome.

Marc S. Sabatine

12

Genetic variability in local Brazilian horse lines using microsatellite markers.  

PubMed

Genetic variability at 11 microsatellite markers was analyzed in five naturalized/local Brazilian horse breeds or genetic groups. Blood samples were collected from 328 animals of the breeds Campeira (Santa Catarina State), Lavradeira (Roraima State), Pantaneira (Pantanal Mato-Grossense), Mangalarga Marchador (Minas Gerais State), as well as the genetic group Baixadeiro (Maranhão State), and the exotic breeds English Thoroughbred and Arab. We found significant genetic variability within evaluated microsatellite loci, with observed heterozygosis varying between 0.426 and 0.768 and polymorphism information content values of 0.751 to 0.914. All breeds showed high inbreeding coefficients and were not in Hardy-Weinberg equilibrium. The smallest genetic distance was seen between the Pantaneira and Arab breeds. The principal component analyzes and Bayesian approach demonstrated that the exotic breeds have had a significant influence on the genetic formation of the local breeds, with introgression of English Throroughbred in Pantaneira and Lavradeira, as well as genetic proximity between the Arab, Pantaneira and Mangalarga Marchador populations. This study shows the need to conserve traits acquired by naturalized horse breeds over centuries of natural selection in Brazil due to the genetic uniqueness of each group, suggesting a reduced gene flow between them. These results reinforce the need to include these herds in animal genetic resource conservation programs to maximize the genetic variability and conserve useful allele combinations. PMID:22576916

Silva, A C M; Paiva, S R; Albuquerque, M S M; Egito, A A; Santos, S A; Lima, F C; Castro, S T; Mariante, A S; Correa, P S; McManus, C M

2012-04-10

13

Balancing genetic uniqueness and genetic variation in determining conservation and translocation strategies: a comprehensive case study of threatened dwarf galaxias, Galaxiella pusilla (Mack) (Pisces: Galaxiidae).  

PubMed

Genetic markers are widely used to define and manage populations of threatened species based on the notion that populations with unique lineages of mtDNA and well-differentiated nuclear marker frequencies should be treated separately. However, a danger of this approach is that genetic uniqueness might be emphasized at the cost of genetic diversity, which is essential for adaptation and is potentially boosted by mixing geographically separate populations. Here, we re-explore the issue of defining management units, focussing on a detailed study of Galaxiella pusilla, a small freshwater fish of national conservation significance in Australia. Using a combination of microsatellite and mitochondrial markers, 51 populations across the species range were surveyed for genetic structure and diversity. We found an inverse relationship between genetic differentiation and genetic diversity, highlighting a long-term risk of deliberate isolation of G. pusilla populations based on protection of unique lineages. Instead, we adopt a method for identifying genetic management units that takes into consideration both uniqueness and genetic variation. This produced a management framework to guide future translocation and re-introduction efforts for G. pusilla, which contrasted to the framework based on a more traditional approach that may overlook important genetic variation in populations. PMID:23432132

Coleman, R A; Weeks, A R; Hoffmann, A A

2013-02-21

14

Genetic uniqueness of the Waorani tribe from the Ecuadorian Amazon  

PubMed Central

South America and especially the Amazon basin is known to be home to some of the most isolated human groups in the world. Here, we report on a study of mitochondrial DNA (mtDNA) in the Waorani from Ecuador, probably the most warlike human population known to date. Seeking to look in more depth at the characterization of the genetic diversity of this Native American tribe, molecular markers from the X and Y chromosomes were also analyzed. Only three different mtDNA haplotypes were detected among the Waorani sample. One of them, assigned to Native American haplogroup A2, accounted for more than 94% of the total diversity of the maternal gene pool. Our results for sex chromosome molecular markers failed to find close genetic kinship between individuals, further emphasizing the low genetic diversity of the mtDNA. Bearing in mind the results obtained for both the analysis of the mtDNA control region and complete mitochondrial genomes, we suggest the existence of a ‘Waorani-specific' mtDNA lineage. According to current knowledge on the phylogeny of haplogroup A2, we propose that this lineage could be designated as subhaplogroup A2s. Its wide predominance among the Waorani people might have been conditioned by severe genetic drift episodes resulting from founding events, long-term isolation and a traditionally small population size most likely associated with the striking ethnography of this Amazonian community. In all, the Waorani constitute a fine example of how genetic imprint may mirror ethnopsychology and sociocultural features in human populations.

Cardoso, S; Alfonso-Sanchez, M A; Valverde, L; Sanchez, D; Zarrabeitia, M T; Odriozola, A; Martinez-Jarreta, B; de Pancorbo, M M

2012-01-01

15

Genetic and biological markers in drug abuse and alcoholism  

SciTech Connect

This book contains 11 selections. Some of the titles are: Polymorphic Gene Marker Studies; Pharmacogenetic Approaches to the Prediction of Drug Response; Genetic Markers of Drug Abuse in Mouse Models; Genetics as a Tool for Identifying Biological Markers of Drug Abuse; and Studies of an Animal Model of Alcoholism.

Braude, M.C.; Chao, H.M.

1986-01-01

16

Mixture model equations for marker-assisted genetic evaluation  

Microsoft Academic Search

Summary Marker-assisted genetic evaluation needs to infer genotypes at quantita- tive trait loci (QTL) based on the information of linked markers. As the inference usually provides the probability distribution of QTL genotypes rather than a specific genotype, marker-assisted genetic evaluation is characterized by the mixture model because of the uncertainty of QTL genotypes. It is, therefore, necessary to develop a

Y. Liu; Z.-B. Zeng

2005-01-01

17

Extensive Genetic Diversity, Unique Population Structure and Evidence of Genetic Exchange in the Sexually Transmitted Parasite Trichomonas vaginalis  

PubMed Central

Background Trichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted infection world-wide. Despite its prevalence, little is known about the genetic diversity and population structure of this haploid parasite due to the lack of appropriate tools. The development of a panel of microsatellite makers and SNPs from mining the parasite's genome sequence has paved the way to a global analysis of the genetic structure of the pathogen and association with clinical phenotypes. Methodology/Principal Findings Here we utilize a panel of T. vaginalis-specific genetic markers to genotype 235 isolates from Mexico, Chile, India, Australia, Papua New Guinea, Italy, Africa and the United States, including 19 clinical isolates recently collected from 270 women attending New York City sexually transmitted disease clinics. Using population genetic analysis, we show that T. vaginalis is a genetically diverse parasite with a unique population structure consisting of two types present in equal proportions world-wide. Parasites belonging to the two types (type 1 and type 2) differ significantly in the rate at which they harbor the T. vaginalis virus, a dsRNA virus implicated in parasite pathogenesis, and in their sensitivity to the widely-used drug, metronidazole. We also uncover evidence of genetic exchange, indicating a sexual life-cycle of the parasite despite an absence of morphologically-distinct sexual stages. Conclusions/Significance Our study represents the first robust and comprehensive evaluation of global T. vaginalis genetic diversity and population structure. Our identification of a unique two-type structure, and the clinically relevant phenotypes associated with them, provides a new dimension for understanding T. vaginalis pathogenesis. In addition, our demonstration of the possibility of genetic exchange in the parasite has important implications for genetic research and control of the disease.

Conrad, Melissa D.; Gorman, Andrew W.; Schillinger, Julia A.; Fiori, Pier Luigi; Arroyo, Rossana; Malla, Nancy; Dubey, Mohan Lal; Gonzalez, Jorge; Blank, Susan; Secor, William E.; Carlton, Jane M.

2012-01-01

18

Genetic markers and population history: Finland revisited  

PubMed Central

The Finnish population in Northern Europe has been a target of extensive genetic studies during the last decades. The population is considered as a homogeneous isolate, well suited for gene mapping studies because of its reduced diversity and homogeneity. However, several studies have shown substantial differences between the eastern and western parts of the country, especially in the male-mediated Y chromosome. This divergence is evident in non-neutral genetic variation also and it is usually explained to stem from founder effects occurring in the settlement of eastern Finland as late as in the 16th century. Here, we have reassessed this population historical scenario using Y-chromosomal, mitochondrial and autosomal markers and geographical sampling covering entire Finland. The obtained results suggest substantial Scandinavian gene flow into south-western, but not into the eastern, Finland. Male-biased Scandinavian gene flow into the south-western parts of the country would plausibly explain the large inter-regional differences observed in the Y-chromosome, and the relative homogeneity in the mitochondrial and autosomal data. On the basis of these results, we suggest that the expression of ‘Finnish Disease Heritage' illnesses, more common in the eastern/north-eastern Finland, stems from long-term drift, rather than from relatively recent founder effects.

Palo, Jukka U; Ulmanen, Ismo; Lukka, Matti; Ellonen, Pekka; Sajantila, Antti

2009-01-01

19

Genetic markers and population history: Finland revisited.  

PubMed

The Finnish population in Northern Europe has been a target of extensive genetic studies during the last decades. The population is considered as a homogeneous isolate, well suited for gene mapping studies because of its reduced diversity and homogeneity. However, several studies have shown substantial differences between the eastern and western parts of the country, especially in the male-mediated Y chromosome. This divergence is evident in non-neutral genetic variation also and it is usually explained to stem from founder effects occurring in the settlement of eastern Finland as late as in the 16th century. Here, we have reassessed this population historical scenario using Y-chromosomal, mitochondrial and autosomal markers and geographical sampling covering entire Finland. The obtained results suggest substantial Scandinavian gene flow into south-western, but not into the eastern, Finland. Male-biased Scandinavian gene flow into the south-western parts of the country would plausibly explain the large inter-regional differences observed in the Y-chromosome, and the relative homogeneity in the mitochondrial and autosomal data. On the basis of these results, we suggest that the expression of 'Finnish Disease Heritage' illnesses, more common in the eastern/north-eastern Finland, stems from long-term drift, rather than from relatively recent founder effects. PMID:19367325

Palo, Jukka U; Ulmanen, Ismo; Lukka, Matti; Ellonen, Pekka; Sajantila, Antti

2009-04-15

20

Unique genetic variation at a species' rear edge is under threat from global climate change  

PubMed Central

Global climate change is having a significant effect on the distributions of a wide variety of species, causing both range shifts and population extinctions. To date, however, no consensus has emerged on how these processes will affect the range-wide genetic diversity of impacted species. It has been suggested that species that recolonized from low-latitude refugia might harbour high levels of genetic variation in rear-edge populations, and that loss of these populations could cause a disproportionately large reduction in overall genetic diversity in such taxa. In the present study, we have examined the distribution of genetic diversity across the range of the seaweed Chondrus crispus, a species that has exhibited a northward shift in its southern limit in Europe over the last 40 years. Analysis of 19 populations from both sides of the North Atlantic using mitochondrial single nucleotide polymorphisms (SNPs), sequence data from two single-copy nuclear regions and allelic variation at eight microsatellite loci revealed unique genetic variation for all marker classes in the rear-edge populations in Iberia, but not in the rear-edge populations in North America. Palaeodistribution modelling and statistical testing of alternative phylogeographic scenarios indicate that the unique genetic diversity in Iberian populations is a result not only of persistence in the region during the last glacial maximum, but also because this refugium did not contribute substantially to the recolonization of Europe after the retreat of the ice. Consequently, loss of these rear-edge populations as a result of ongoing climate change will have a major effect on the overall genetic diversity of the species, particularly in Europe, and this could compromise the adaptive potential of the species as a whole in the face of future global warming.

Provan, Jim; Maggs, Christine A.

2012-01-01

21

Molecular pathology in basal cell cancer with p53 as a genetic marker  

Microsoft Academic Search

Human basal cell cancer (BCC) has unique growth characteristics with virtual inability to metastasize. We investigated clonality and genetic progression using p53 mutations as marker. Sampling was done through microdissection of frozen immunohistochemically stained 16 ?m slices of tumors. From 11 BCC tumors 78 samples were analysed. Direct DNA sequencing of exons 5 – 8 was performed, haplotypes were determined

Fredrik Pontén; Cecilia Berg; Afshin Ahmadian; Zhi-Ping Ren; Monica Nistér; Joakim Lundeberg; Mathias Uhlén; Jan Pontén

1997-01-01

22

Genetic Diversity in Cultivated Groundnut Based on SSR Markers  

Microsoft Academic Search

Peanut (Arachis hypogaea L.) is an important source crop for edible oil and protein. It is important to identify the genetic diversity of peanut genetic resources for cultivar development and evaluation of peanut accessions. Thirty-four SSR markers were used to assess the genetic variation of four sets of twenty-four accessions each from the four botanical varieties of the cultivated peanut.

Ronghua Tang; Guoqing Gao; Liangqiong He; Zhuqiang Han; Shihua Shan; Ruichun Zhong; Cuiqiu Zhou; Jing Jiang; Yangrui Li; Weijian Zhuang

2007-01-01

23

Molecular Genetic Features of Polyploidization and Aneuploidization Reveal Unique Patterns for Genome Duplication in Diploid Malus  

PubMed Central

Polyploidization results in genome duplication and is an important step in evolution and speciation. The Malus genome confirmed that this genus was derived through auto-polyploidization, yet the genetic and meiotic mechanisms for polyploidization, particularly for aneuploidization, are unclear in this genus or other woody perennials. In fact the contribution of aneuploidization remains poorly understood throughout Plantae. We add to this knowledge by characterization of eupolyploidization and aneuploidization in 27,542 F1 seedlings from seven diploid Malus populations using cytology and microsatellite markers. We provide the first evidence that aneuploidy exceeds eupolyploidy in the diploid crosses, suggesting aneuploidization is a leading cause of genome duplication. Gametes from diploid Malus had a unique combinational pattern; ova preserved euploidy exclusively, while spermatozoa presented both euploidy and aneuploidy. All non-reduced gametes were genetically heterozygous, indicating first-division restitution was the exclusive mode for Malus eupolyploidization and aneuploidization. Chromosome segregation pattern among aneuploids was non-uniform, however, certain chromosomes were associated for aneuploidization. This study is the first to provide molecular evidence for the contribution of heterozygous non-reduced gametes to fitness in polyploids and aneuploids. Aneuploidization can increase, while eupolyploidization may decrease genetic diversity in their newly established populations. Auto-triploidization is important for speciation in the extant Malus. The features of Malus polyploidization confer genetic stability and diversity, and present heterozygosity, heterosis and adaptability for evolutionary selection. A protocol using co-dominant markers was proposed for accelerating apple triploid breeding program. A path was postulated for evolution of numerically odd basic chromosomes. The model for Malus derivation was considerably revised. Impacts of aneuploidization on speciation and evolution, and potential applications of aneuploids and polyploids in breeding and genetics for other species were evaluated in depth. This study greatly improves our understanding of evolution, speciation, and adaptation of the Malus genus, and provides strategies to exploit polyploidization in other species.

Considine, Michael J.; Wan, Yizhen; D'Antuono, Mario F.; Zhou, Qian; Han, Mingyu; Gao, Hua; Wang, Man

2012-01-01

24

PCR-based landmark unique gene (PLUG) markers effectively assign homoeologous wheat genes to A, B and D genomes  

PubMed Central

Background EST-PCR markers normally represent specific products from target genes, and are therefore effective tools for genetic analysis. However, because wheat is an allohexaploid plant, PCR products derived from homoeologous genes are often simultaneously amplified. Such products may be easier to differentiate if they include intron sequences, which are more polymorphic than exon sequences. However, genomic sequence data for wheat are limited; therefore it is difficult to predict the location of introns. By using the similarities in gene structures between rice and wheat, we developed a system called PLUG (PCR-based Landmark Unique Gene) to design primers so that PCR products include intron sequences. We then investigated whether products amplified using such primers could serve as markers able to distinguish multiple products derived from homoeologous genes. Results The PLUG system consists of the following steps: (1) Single-copy rice genes (Landmark Unique Gene loci; LUGs) exhibiting high degrees of homology to wheat UniGene sequences are extracted; (2) Alignment analysis is carried out using the LUGs and wheat UniGene sequences to predict exon-exon junctions, and LUGs which can be used to design wheat primers flanking introns (TaEST-LUGs) are extracted; and (3) Primers are designed in an interactive manner. From a total of 4,312 TaEST-LUGs, 24 loci were randomly selected and used to design primers. With all of these primer sets, we obtained specific, intron-containing products from the target genes. These markers were assigned to chromosomes using wheat nullisomic-tetrasomic lines. By PCR-RFLP analysis using agarose gel electrophoresis, 19 of the 24 markers were located on at least one chromosome. Conclusion In the development of wheat EST-PCR markers capable of efficiently sorting products derived from homoeologous genes, it is important to design primers able to amplify products that include intron sequences with insertion/deletion polymorphisms. Using the PLUG system, wheat EST sequences that can be used for marker development are selected based on comparative genomics with rice, and then primer sets flanking intron sequences are prepared in an interactive, semi-automatic manner. Hence, the PLUG system is an effective tool for large-scale marker development.

Ishikawa, Goro; Yonemaru, Junichi; Saito, Mika; Nakamura, Toshiki

2007-01-01

25

RESISTANCE GENE HOMOLOGUES IN THEOBROMA CACAO AS USEFUL GENETIC MARKERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Resistance gene homologues (RGH) sequences have been developed into useful genetic markers for marker-assisted selection (MAS) of disease resistant Theobroma cacao. a plasmid library of amplified fragments was created from seven different cultivars of cacao. Over 600 cloned recombinant amplicons w...

26

A genetic map of potato ( Solanum tuberosum ) integrating molecular markers, including transposons, and classical markers  

Microsoft Academic Search

A genetic map of potato (Solanum tuberosum L.) integrating molecular markers with morphological and isozyme markers was constructed using a backcross population of 67 diploid potato plants. A general method for map construction is described that differs from previous methods employed in potato and other outbreeding plants. First, separate maps for the female and male parents were constructed. The female

J. M. E. Jacobs; H. J. Van Eek; P. F. P. Arens; B. Verkerk-Bakker; B. te Lintel Hekkert; H. J. M. Bastiaanssen; A. El-Kharbotly; A. Pereira; E. Jacobsen; W. J. Stiekema

1995-01-01

27

Toward Diagnostic and Phenotype Markers for Genetically Transmitted Speech Delay  

ERIC Educational Resources Information Center

Converging evidence supports the hypothesis that the most common subtype of childhood speech sound disorder (SSD) of currently unknown origin is genetically transmitted. We report the first findings toward a set of diagnostic markers to differentiate this proposed etiological subtype (provisionally termed "speech delay-genetic") from other…

Shriberg, Lawrence D.; Lewis, Barbara A.; Tomblin, J. Bruce; McSweeny, Jane L.; Karlsson, Heather B.; Scheer, Alison R.

2005-01-01

28

Natural bioluminescence as a genetic marker for ophiuroid species  

Microsoft Academic Search

Bioluminescence is the emission of visible light by living organisms. This amazing property is used in various research fields such as genetics, molecular biology, chemistry, etc. The aim of this work was to gather evidence that bioluminescence could also be used as a genetic marker in various luminescent species. Previous studies with the brittlestar Amphipholis squamata have shown that bioluminescence

Samuel Dupont; Jérôme Mallefet; Yannick Dewael

2001-01-01

29

Construction of fingerprinting and genetic diversity of mulberry cultivars in China by ISSR markers.  

PubMed

The ISSR fingerprintings of 24 mulberry cultivars were constructed. Totally 80 bands were produced using 17 primers selected from 20 primers. Of them, 40 bands showed polymorphism. From the bands amplified, there were three independent ways to identify the mulberry varieties, such as unique ISSR markers, unique band patterns and a combination of the band patterns provided by different primers. ISSRs were very effective in differentiating the mulberry varieties. The mean genetic similarity coefficient, the mean Nei's gene diversity (h), and the mean Shannon's Information index (I) of mulberry cultivars were 0.8731, 0.1210, and 0.1942, respectively. This suggests that the genetic diversity of mulberry cultivars was low and the genetic base was narrow. Both UPGMA cluster and PCA (Principal Coordinates Analysis) analysis showed clear genetic relationships among the 24 mulberry cultivars. The major clusters were related to known pedigree relationships. PMID:16980132

Zhao, Wei-Guo; Miao, Xue-Xia; Zang, Bo; Zhang, Lin; Pan, Yi-Le; Huang, Yong-Ping

2006-09-01

30

[Study of genetic markers of duodenal ulcer].  

PubMed

The results of determination of various hereditary predisposition markers in peptic ulcer are given: in the population, in patients with duodenal ulcer and in their siblings (risk group). Of importance for revealing subjects with hereditary predisposition to duodenal ulcer are the clinico-genealogical analysis, determination of the blood group, especially in simultaneous determination of a "secretory status" ("status of non-secretion" of the ABH blood system agglutinogen in the saliva), increase in the mass of parietal cells and, to some extent, of the distinguishing features of dermatoglyphics (in combination with the above markers). Determination of taste sensitivity to phenylthiocarbamide is non-informative. PMID:2770215

Tsimmerman, Ia S; Onosova, E A; Tsimmerman, I Ia

1989-05-01

31

Novel microsatellite markers suitable for genetic studies in the white button mushroom Agaricus bisporus.  

PubMed

Co-dominant microsatellite molecular markers were obtained from the Agaricus bisporus cultivated mushroom. Their potential for both the molecular characterisation of commercial strains and the monitoring of the intraspecific genetic variation was demonstrated. The analysis of 673 unique sequences issued from public database and 59 from an enriched A. bisporus genomic library resulted in the development of a total of 33 single sequence repeat or microsatellite (SSR) markers. Their usefulness for genetic analysis was assessed on 28 strains, which include six cultivars representative of traditional lineage, two hybrids and 20 strains originating from wild populations. A. bisporus SSR markers displayed each from two to ten alleles, with an average of 5.6 alleles per locus. The observed heterozygosity ranged from 0 to 0.88. Cluster analysis resulting from SSR fingerprintings was in agreement with published A. bisporus population structure. A combination of only three selected SSR markers was sufficient to discriminate unambiguously 27 out of 28 distinct genotypes. However, the two genetically related hybrids were not distinguishable. Multiplexing was tested, and up to seven loci could be genotyped simultaneously. We are therefore reporting the first development in A. bisporus of a set of microsatellite markers powerful and suitable for genetic analysis. PMID:19455324

Foulongne-Oriol, Marie; Spataro, Cathy; Savoie, Jean-Michel

2009-05-12

32

Genetic mapping with SNP markers in Drosophila  

Microsoft Academic Search

Map-based positional cloning of Drosophila melanogaster genes is hampered by both the time-consuming, error-prone nature of traditional methods for genetic mapping and the diffi- culties in aligning the genetic and cytological maps with the genome sequence. The identification of sequence polymor- phisms in the Drosophila genome will make it possible to map mutations directly to the genome sequence with high

Jürg Berger; Takashi Suzuki; Kirsten-André Senti; Janine Stubbs; Gotthold Schaffner; Barry J. Dickson

2001-01-01

33

Single nucleotide polymorphism markers for genetic mapping in Drosophila melanogaster  

SciTech Connect

For nearly a century, genetic analysis in Drosophila melanogaster has been a powerful tool for analyzing gene function, yet Drosophila lacks the molecular genetic mapping tools that have recently revolutionized human, mouse and plant genetics. Here, we describe the systematic characterization of a dense set of molecular markers in Drosophila using an STS-based physical map of the genome. We identify 474 biallelic markers in standard laboratory strains of Drosophila that the genome. The majority of these markers are single nucleotide polymorphisms (SNPs) and sequences for these variants are provided in an accessible format. The average density of the new markers is 1 marker per 225 kb on the autosomes and 1 marker per 1 Mb on the X chromosome. We include in this survey a set of P-element strains that provide additional utility for high-resolution mapping. We demonstrate one application of the new markers in a simple set of crosses to map a mutation in the hedgehog gene to an interval of <1 Mb. This new map resource significantly increases the efficiency and resolution of recombination mapping and will be of immediate value to the Drosophila research community.

Hoskins, Roger A.; Phan, Alexander C.; Naeemuddin, Mohammed; Mapa, Felipa A.; Ruddy, David A.; Ryan, Jessica J.; Young, Lynn M.; Wells, Trent; Kopczynski, Casey; Ellis, Michael C.

2001-04-16

34

Novel microsatellite markers suitable for genetic studies in the white button mushroom Agaricus bisporus  

Microsoft Academic Search

Co-dominant microsatellite molecular markers were obtained from the Agaricus bisporus cultivated mushroom. Their potential for both the molecular characterisation of commercial strains and the monitoring of\\u000a the intraspecific genetic variation was demonstrated. The analysis of 673 unique sequences issued from public database and\\u000a 59 from an enriched A. bisporus genomic library resulted in the development of a total of 33

Marie Foulongne-Oriol; Cathy Spataro; Jean-Michel Savoie

2009-01-01

35

Preliminary genetic linkage map of Miscanthus sinensis with RAPD markers.  

PubMed

We have used an "offspring cross" mapping strategy in combination with the random amplified polymorphic DNA (RAPD) assay to construct the first genetic map of the species Miscanthus sinensis (2 n = 2 x = 38). This map is based on an outbred population of 89 individuals resulting from the cross between two genotypes from a previously designed cross. Consequently, both parents are fullsibs. The same proportion of bi-parental markers (heterozygotic in both parents) and pseudo-testcross markers (heterozygotic in one parent and null in the other), mono-parental markers, have been obtained. A total of 383 RAPD markers were analysed within the 89 F1 plants. Out of these markers, 257 were mapped into 28 linkage groups which spanned a total map length of around 1,074.5 cM with an average density of 4.2 cM per marker. Out of 257 mapped markers, 62 were inherited from F1.1 (P1), 63 from F1.7 (P7) and 132 were bi-parental markers. The contribution to the map was equal from both parents. This map provides a useful tool for genetic analyses of agronomically interesting characters in M. sinensis such as flowering, yield, plant height, stem diameter and mineral constitution. The offspring cross mapping strategy is proposed to obtain a higher efficiency in developing integrated maps including both parents. PMID:12582920

Atienza, G.; Satovic, Z.; Petersen, K.; Dolstra, O.; Martín, A.

2002-06-19

36

Integrated microsatellite markers suitable for genetic studies of cytokine genes.  

PubMed

A panel of 13 highly informative dinucleotide repeats which are genetic markers for 17 cytokine genes and receptors is described. The marker panel is designed for use in fluorescence based semi-automated genotyping, with primers designed and labelled such that all 13 markers can be analysed in a single lane of a gel. Cytokine and cytokine receptors have a potential role in many diseases and pathological processes. Evidence suggests that cytokine production in vivo is influenced by polymorphisms within regulatory sequences of these genes. Genetic investigation of disease genes often requires genotyping of very large numbers of individuals. This panel of markers will, therefore, provide a useful tool to those wishing to undertake family-based linkage analysis studies of cytokine genes or large-scale association studies. PMID:9632534

John, S; Korman, Y; Ollier, W; Worthington, J

1998-06-01

37

DNA marker applications to molecular genetics and genomics in tomato  

PubMed Central

Tomato is an important crop and regarded as an experimental model of the Solanaceae family and of fruiting plants in general. To enhance breeding efficiency and advance the field of genetics, tomato has been subjected to DNA marker studies as one of the earliest targets in plants. The developed DNA markers have been applied to the construction of genetic linkage maps and the resultant maps have contributed to quantitative trait locus (QTL) and gene mappings for agronomically important traits, as well as to comparative genomics of Solanaceae. The recently released whole genome sequences of tomato enable us to develop large numbers of DNA markers comparatively easily, and even promote new genotyping methods without DNA markers. In addition, databases for genomes, DNA markers, genetic linkage maps and other omics data, e.g., transcriptome, proteome, metabolome and phenome information, will provide useful information for molecular breeding in tomatoes. The use of DNA marker technologies in conjunction with new breeding techniques will promise to advance tomato breeding.

Shirasawa, Kenta; Hirakawa, Hideki

2013-01-01

38

Marker reconstitution mutagenesis: a simple and efficient reverse genetic approach.  

PubMed

A novel reverse genetic approach termed 'marker reconstitution mutagenesis' was designed to generate mutational allelic series in genes of interest. This approach consists of two simple steps which utilize two selective markers. First, using one selective marker, a partial fragment of another selective marker gene is inserted adjacently to a gene of interest by homologous recombination. Second, random mutations are introduced precisely into the gene of interest, together with the reconstitution of the latter selective marker by homologous recombination. This approach was successfully tested for several genes in the fission yeast Schizosaccharomyces pombe. It circumvents the problems encountered with other methods and should be adaptable to any organism that incorporates exogenous DNA by homologous recombination. PMID:21360732

Tang, Xie; Huang, Junqi; Padmanabhan, Anup; Bakka, Kavya; Bao, Yun; Tan, Brenda Yuelin; Cande, W Zacheus; Balasubramanian, Mohan K

2010-11-22

39

Genetic prognostic markers in colorectal cancer.  

PubMed Central

The contribution of molecular genetics to colorectal cancer has been restricted largely to relatively rare inherited tumours and to the detection of germline mutations predisposing to these cancers. However, much is now also known about somatic events leading to colorectal cancer. A number of studies has been undertaken examining possible relations between genetic features and prognostic indices. While many of these studies are small and inconclusive, it is clear that a number of different pathways exist for the development of this cancer and some molecular characteristics correlate with clinicopathological features. With the advent of methods for the rapid genotyping of large numbers of colorectal cancers, it should be possible to evaluate fully the clinical usefulness of colorectal cancer genotypes through multivariate analyses.

Houlston, R S; Tomlinson, I P

1997-01-01

40

Pro-inflammatory genetic markers of atherosclerosis.  

PubMed

Atherosclerosis (AS) is a chronic, progressive, multifactorial disease mostly affecting large and medium-sized elastic and muscular arteries. It has formerly been considered a bland lipid storage disease. Currently, multiple independent pathways of evidence suggest this pathological condition is a peculiar form of inflammation, triggered by cholesterol-rich lipoproteins and influenced both by environmental and genetic factors. The Human Genome Project opened up the opportunity to dissect complex human traits and to understand basic pathways of multifactorial diseases such as AS. Population-based association studies have emerged as powerful tools for examining genes with a role in common multifactorial diseases that have a strong environmental component. These association studies often estimate the risk of developing a certain disease in carriers and non-carriers of a particular genetic polymorphism. Dissecting out the influence of pro-inflammatory genes within the complex pathophysiology of AS and its complications will help to provide a more complete risk assessment and complement known classical cardiovascular risk factors. The detection of a risk profile will potentially allow both the early identification of individuals susceptible to disease and the possible discovery of potential targets for drug or lifestyle modification; i.e. it will open the door to personalized medicine. PMID:23591672

Incalcaterra, Egle; Accardi, Giulia; Balistreri, Carmela Rita; Caimi, Gregorio; Candore, Giuseppina; Caruso, Marco; Caruso, Calogero

2013-06-01

41

Methods and Compositions for Correlating Genetic Markers with Cardiovascular Disease.  

National Technical Information Service (NTIS)

The present invention provides methods of identifying a subject having an increased or decreased risk of developing cardiovascular disease, comprising: (a) correlating the presence of one or more genetic markers in chromosome 3q13.31 with an increased or ...

J. M. Vance P. J. Goldschmidt S. G. Gregory W. E. Kraus

2005-01-01

42

Genetic diversity in Hemileia vastatrix based on RAPD markers  

Microsoft Academic Search

Random amplified polymorphic DNA (RAPD) was used to assess the genetic structure of Hemileia vastatrix populations. Forty-five rust iso- lates with different virulence spectra and from dif- ferent hosts and geographical regions were ana- lyzed. Out of 45 bands, generated with three RAPD primers, 35 (78%) were polymorphic and scored as molecular markers. Cluster analysis exhibits unstruc- tured variability of

M. M. C. Gouveia; A. Ribeiro; V. M. P. Varzea; C. J. Rodrigues

2005-01-01

43

Prostate cancer risk-associated genetic markers and their potential clinical utility  

PubMed Central

Prostate cancer (PCa) is one of the most common cancers among men in Western developed countries and its incidence has increased considerably in many other parts of the world, including China. The etiology of PCa is largely unknown but is thought to be multifactorial, where inherited genetics plays an important role. In this article, we first briefly review results from studies of familial aggregation and genetic susceptibility to PCa. We then recap key findings of rare and high-penetrance PCa susceptibility genes from linkage studies in PCa families. We devote a significant portion of this article to summarizing discoveries of common and low-penetrance PCa risk-associated single-nucleotide polymorphisms (SNPs) from genetic association studies in PCa cases and controls, especially those from genome-wide association studies (GWASs). A strong focus of this article is to review the literature on the potential clinical utility of these implicated genetic markers. Most of these published studies described PCa risk estimation using a genetic score derived from multiple risk-associated SNPs and its utility in determining the need for prostate biopsy. Finally, we comment on the newly proposed concept of genetic score; the notion is to treat it as a marker for genetic predisposition, similar to family history, rather than a diagnostic marker to discriminate PCa patients from non-cancer patients. Available evidence to date suggests that genetic score is an objective and better measurement of inherited risk of PCa than family history. Another unique feature of this article is the inclusion of genetic association studies of PCa in Chinese and Japanese populations.

Xu, Jianfeng; Sun, Jielin; Zheng, S Lilly

2013-01-01

44

Behavioral and genetic markers of sleepiness.  

PubMed

Neurobehavioral responses to acute total and chronic partial sleep deprivation occur in healthy adults and are particularly evident in vigilant attention performance. There are large inter-individual differences in the degree of cognitive deficits--such differences are manifested in proportionality between the mean and variance as sleep loss progresses. It has recently been demonstrated via laboratory experiments that differential neurobehavioral vulnerability to sleep deprivation is not random--but rather is stable and trait-like--strongly suggesting a phenotypic response with possible genotypic involvement. These experiments also showed that vulnerability was not explained by subjects' baseline functioning or a number of other potential predictors. Differential vulnerability has been shown to extend to chronic partial sleep deprivation. One potential genetic biomarker for such differential vulnerability is the human leukocyte antigen (HLA) DQB1*0602, an allele which we recently demonstrated predicts interindividual differences in sleepiness, physiological sleep, and fatigue to chronic partial sleep deprivation in healthy adults. Determination of biomarkers of individual differences to sleep loss will help identify those individuals in the general population who are most in need of prevention of sleep debt and in need of effective countermeasures for sleep loss; will further understanding and management of vulnerability to excessive sleepiness due to common sleep and medical disorders; and will inform public policies pertaining to the need for adequate sleep. PMID:22003324

Goel, Namni; Dinges, David F

2011-10-15

45

The genetic signature of perineuronal oligodendrocytes reveals their unique phenotype.  

PubMed

Oligodendrocytes--best known for assembling central nervous system myelin--can be categorized as precursors, myelin-forming cells and non-myelinating perineuronal cells. Perineuronal oligodendrocytes have been well characterized morphologically and ultrastructurally, but knowledge about their function remains scanty. It has been proposed that perineuronal oligodendrocytes support neurons and, following injury, transform into myelin-synthesizing cells. Recent findings implicating perineuronal oligodendrocytes in cytoarchitectural abnormalities in the prefrontal cortex of schizophrenia and other psychiatric disorders shed new light on these cells. We have obtained the genetic signature of perineuronal oligodendrocytes by identifying gene expression differences between oligodendrocyte subpopulations using cell-specific tags, microarray technology, quantitative time-resolved polymerase chain reaction and bioinformatics tools. We show that perineuronal cells are the progeny of oligodendrocyte progenitors and, hence, are members of the oligodendrocyte lineage. Physiologically they exhibit a novel phenotype. Their expression of PDGFR-?? and its growth factor ligand PDGF-CC sets them apart from members of their lineage as this receptor precludes their response to the same growth factors that act on myelinating cells. Their coordinate expression and context-specific usage of transcription factors Olig2, Ascl1 and Pax6, together with the prominent presence of transcription factors Pea3, Lhx2 and Otx2--not hitherto linked to the oligodendrocyte lineage--suggested a cell with features that blur the boundary between a neuron and a glial cell. But they also maintain a reservoir of untranslated transcripts encoding major myelin proteins presumably for a demyelinating episode. This first molecular characterization of perineuronal oligodendrocytes revealed the striking difference between the myelinating and non-myelinating phenotypes. PMID:22132705

Szuchet, Sara; Nielsen, Joseph A; Lovas, Gabor; Domowicz, Miriam S; de Velasco, Javier M; Maric, Dragan; Hudson, Lynn D

2011-12-02

46

Twenty-one polymorphic markers from human chromosome 12 for integration of genetic and physical maps  

SciTech Connect

Twenty-one physically mapped, polymorphic markers have been developed from a chromosome 12-specific cosmid library. The markers consist of CA repeat-containing sequence-tagged sites (STSs) derived from cosmid clones mapped by fluorescence in situ hybridization (FISH). Three methods for determining the sequence flanking CA microsatellites were used, including one using degenerate primer sets for direct sequence analysis. Oligonucleotide primer pairs suitable for use in polymerase chain reaction (PCR) were selected from the sequences flanking the CA microsatellite and were tested for their ability to generate unique PCR products. The informativeness of these STSs as genetic markers was determined by typing 10 unrelated individuals who are part of the Centre d'Etude du Polymorphisme Humaine (EPH) pedigrees. Eleven of the 21 FISH-mapped, polymorphic STSs are heterozygous in 7 or more of the individuals tested. Since these markers are derived from physically mapped cosmids, genetic linkage analysis with them will facilitate the integration of the developing physical and genetic maps of chromosome 12. 29 refs., 4 figs., 2 tabs.

LeBlanc-Straceski, J.M.; Kissel, H.; Murtaugh, L.; Kucherlapati, R.; Montogmery, K.T.; Krauter, K.S. (Albert Einstein College of Medicine, Bronx, NY (United States)); Tsai, P.; Ward, D.C. (Yale Univ. Medical School, New Haven, CT (United States))

1994-01-15

47

RAPD, ISSR AND AFLP MARKERS REPRESENTING VARIOUS LINKAGE REGIONS OF A WATERMELON GENETIC MAP ARE POLYMORPHIC AMONG CLOSELY RELATED WATERMELON CULTIVARS  

Technology Transfer Automated Retrieval System (TEKTRAN)

A genetic linkage map was previously constructed for watermelon using a wide testcross population {[Griffin 14113 (C. lanatus var. citroides) x New Hampshire Midget; NHM (C. lanatus var. lanatus)] x U.S. PI 386015 (C. colocynthis)}. Most markers (44 RAPD, 15 ISSR and 48 AFLP markers) unique to NHM a...

48

Neural Markers of Genetic Vulnerability to Drug Addiction  

Microsoft Academic Search

\\u000a This chapter will summarize genetics findings derived from various strategies and highlight important neural markers (or correlates)\\u000a in some specific and extensively studied genes. Most studies highlighted here focus on alcohol and nicotine dependence (AD\\u000a and ND, respectively). AD and ND are among the most prevalent addictive disorders worldwide, are among the best studied, and\\u000a are also associated globally with

Daniel J. Müller; Olga Likhodi; Andreas Heinz

49

Major histocompatibility locus genetic markers of beryllium sensitization and disease  

Microsoft Academic Search

Major histocompatibility locus genetic markers of beryllium sensitization and disease. C. Saltini, L. Richeldi, M. Losi, M. Amicosante, C. Voorter, E. van den Berg-Loonen, R.A. Dweik, H.P. Wiedemann, D.C. Deubner, C. Tinelli. #ERS Journals Ltd 2001. ABSTRACT: Hypersensitivity to beryllium (Be) is found in 1-16% of exposed workers undergoing immunological screening for beryllium disease using the beryllium lym- phocyte proliferation

C. Saltini; L. Richeldi; M. Losi; M. Amicosante; C. Voorter; E. Van Den Berg-Loonen; R. A. Dweik; H. P. Wiedemann; D. C. Deubner; C. Tinelli

2001-01-01

50

Genetic markers for doubled haploid response in barley  

Microsoft Academic Search

In order to analyse the genetic control of anther culture response in barley, a doubled-haploid (DH) population from the cross\\u000a between a medium responsive cultivar ‘Dobla’ and the model cultivar ‘Igri’ was produced. A linkage map was constructed with\\u000a 91 markers. A sub-population of 41 lines was characterised for different components of the anther culture response, and was\\u000a used for

Xi-Wen Chen; Luís Cistué; María Muñoz-Amatriaín; Miguel Sanz; Ignacio Romagosa; Ana-María Castillo; María-Pilar Vallés

2007-01-01

51

Genetic Kinship Investigation from Blood Groups to DNA Markers  

PubMed Central

The forensic application of hereditary characteristics became possible after the discovery of human blood groups by Karl Landsteiner in 1901. The foundation for their use in kinship investigation was laid by Emil von Dungern and Ludwig Hirschfeld in 1910 by clarification of the inheritance of the ABO groups. Up to the middle of the 20th century further red cell membrane systems were discovered. From the 1920s Fritz Schiff and Georg Strassmann fought for the introduction of blood groups into forensic kinship investigation. A new era of hemogenetics was opened from 1955 as genetic polymorphisms were described in serum proteins. Starting in 1958 there followed the complex HLA system of white blood cells, which from 1963 was joined by polymophisms in erythrocyte enzymes. Therefore, from the 1980s, it was possible to clarify the majority of kinship cases with a combination of conventional markers. From 1990 to 2000 the conventional markers were gradually replaced by the more effective DNA markers. Simultaneously typing shifted from the phenotype level to the genotype level. The genomic structure of conventional genetic markers could also now be explained. As a reflection of scientific progress the legal situation also changed, particularly in the form of the official guidelines for kinship investigation.

Geserick, Gunther; Wirth, Ingo

2012-01-01

52

Genetic variability in Brazilian wheat cultivars assessed by microsatellite markers  

PubMed Central

Wheat (Triticum aestivum) is one of the most important food staples in the south of Brazil. Understanding genetic variability among the assortment of Brazilian wheat is important for breeding. The aim of this work was to molecularly characterize the thirty-six wheat cultivars recommended for various regions of Brazil, and to assess mutual genetic distances, through the use of microsatellite markers. Twenty three polymorphic microsatellite markers (PMM) delineated all 36 of the samples, revealing a total of 74 simple sequence repeat (SSR) alleles, i.e. an average of 3.2 alleles per locus. Polymorphic information content (PIC value) calculated to assess the informativeness of each marker ranged from 0.20 to 0.79, with a mean of 0.49. Genetic distances among the 36 cultivars ranged from 0.10 (between cultivars Ocepar 18 and BRS 207) to 0.88 (between cultivars CD 101 and Fudancep 46), the mean distance being 0.48. Twelve groups were obtained by using the unweighted pair-group method with arithmetic means analysis (UPGMA), and thirteen through the Tocher method. Both methods produced similar clusters, with one to thirteen cultivars per group. The results indicate that these tools may be used to protect intellectual property and for breeding and selection programs.

2009-01-01

53

Genetic relationships between Lolium (Poaceae) species revealed by RAPD markers.  

PubMed

The genus Lolium is one of the most important groupings of temperate forage grasses, including about eight recognized species that are native to some temperate and subtropical regions of the northern hemisphere. We examined genetic relationships among 18 accessions representing all Lolium species using RAPD markers. Among 50 random primers that we screened, 13 gave reproducible amplification banding patterns. Each of these 13 primers generated 19-43 scorable fragments. A total of 367 RAPD fragments were detected, of which 95.9% were polymorphic across all the Lolium accessions. Dice's coefficient of dissimilarity ranged from 0.016 to 0.622, which is indicative of substantial genetic variations in these Lolium accessions. A neighbor-joining cluster analysis, with bootstrap permutation, produced an unrooted dendrogram, which grouped 18 accessions into two main clades, supporting high bootstrap values (98 and 96%). The first clade included the self-pollinated species, L. persicum, L. temulentum, L. remotum, and L. subulatum. The cross-pollinated species, i.e., L. multiflorum, L. perenne, L. rigidum, and L. canariense, composed the second clade, in which L. canariense formed a distinct subclade, indicating its higher genetic separation from other allogamous species. The value of r = 0.97 in the Mantel test for cophenetic correlation applied to the cluster analysis indicated the high degree of fit of the accessions to a group. A principal coordinate analysis, whose first three coordinates explained 72.6% of the variation, showed similar groupings as in the cluster analysis. The genetic relationships estimated by the polymorphism of RAPD markers are basically in agreement with those previously inferred with other genetic markers. PMID:23546973

Ma, X; Gu, X-Y; Chen, T-T; Chen, S-Y; Huang, L-K; Zhang, X-Q

2013-03-11

54

Informativeness of Genetic Markers for Inference of Ancestry*  

PubMed Central

Inference of individual ancestry is useful in various applications, such as admixture mapping and structured-association mapping. Using information-theoretic principles, we introduce a general measure, the informativeness for assignment (In), applicable to any number of potential source populations, for determining the amount of information that multiallelic markers provide about individual ancestry. In a worldwide human microsatellite data set, we identify markers of highest informativeness for inference of regional ancestry and for inference of population ancestry within regions; these markers, which are listed in online-only tables in our article, can be useful both in testing for and in controlling the influence of ancestry on case-control genetic association studies. Markers that are informative in one collection of source populations are generally informative in others. Informativeness of random dinucleotides, the most informative class of microsatellites, is five to eight times that of random single-nucleotide polymorphisms (SNPs), but 2%–12% of SNPs have higher informativeness than the median for dinucleotides. Our results can aid in decisions about the type, quantity, and specific choice of markers for use in studies of ancestry.

Rosenberg, Noah A.; Li, Lei M.; Ward, Ryk; Pritchard, Jonathan K.

2003-01-01

55

Genetic characterization of fig tree mutants with molecular markers.  

PubMed

The fig (Ficus carica L.) is a fruit tree of great world importance and, therefore, the genetic improvement becomes an important field of research for better crops, being necessary to gather information on this species, mainly regarding its genetic variability so that appropriate propagation projects and management are made. The improvement programs of fig trees using conventional procedures in order to obtain new cultivars are rare in many countries, such as Brazil, especially due to the little genetic variability and to the difficulties in obtaining plants from gamete fusion once the wasp Blastophaga psenes, responsible for the natural pollinating, is not found in Brazil. In this way, the mutagenic genetic improvement becomes a solution of it. For this reason, in an experiment conducted earlier, fig plants formed by cuttings treated with gamma ray were selected based on their agronomic characteristics of interest. We determined the genetic variability in these fig tree selections, using RAPD and AFLP molecular markers, comparing them to each other and to the Roxo-de-Valinhos, used as the standard. For the reactions of DNA amplification, 140 RAPD primers and 12 primer combinations for AFLP analysis were used. The selections did not differ genetically between themselves and between them and the Roxo-de-Valinhos cultivar. Techniques that can detect polymorphism between treatments, such as DNA sequencing, must be tested. The phenotypic variation of plants may be due to epigenetic variation, necessitating the use of techniques with methylation-sensitive restriction enzymes. PMID:22911583

Rodrigues, M G F; Martins, A B G; Desidério, J A; Bertoni, B W; Alves, M C

2012-08-06

56

Genetic diversity analysis of common beans based on molecular markers.  

PubMed

A core collection of the common bean (Phaseolus vulgaris L.), representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico) Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions) was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each), as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP) +3/+3 primer combinations and seven simple sequence repeats (SSR) loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA) and molecular variance (AMOVA) analyses. AFLP analysis produced 530 bands (88.5% polymorphic) while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus). AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation. PMID:22215964

Gill-Langarica, Homar R; Muruaga-Martínez, José S; Vargas-Vázquez, M L Patricia; Rosales-Serna, Rigoberto; Mayek-Pérez, Netzahualcoyotl

2011-10-01

57

Genetic diversity analysis of common beans based on molecular markers  

PubMed Central

A core collection of the common bean (Phaseolus vulgaris L.), representing genetic diversity in the entire Mexican holding, is kept at the INIFAP (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias, Mexico) Germplasm Bank. After evaluation, the genetic structure of this collection (200 accessions) was compared with that of landraces from the states of Oaxaca, Chiapas and Veracruz (10 genotypes from each), as well as a further 10 cultivars, by means of four amplified fragment length polymorphisms (AFLP) +3/+3 primer combinations and seven simple sequence repeats (SSR) loci, in order to define genetic diversity, variability and mutual relationships. Data underwent cluster (UPGMA) and molecular variance (AMOVA) analyses. AFLP analysis produced 530 bands (88.5% polymorphic) while SSR primers amplified 174 alleles, all polymorphic (8.2 alleles per locus). AFLP indicated that the highest genetic diversity was to be found in ten commercial-seed classes from two major groups of accessions from Central Mexico and Chiapas, which seems to be an important center of diversity in the south. A third group included genotypes from Nueva Granada, Mesoamerica, Jalisco and Durango races. Here, SSR analysis indicated a reduced number of shared haplotypes among accessions, whereas the highest genetic components of AMOVA variation were found within accessions. Genetic diversity observed in the common-bean core collection represents an important sample of the total Phaseolus genetic variability at the main Germplasm Bank of INIFAP. Molecular marker strategies could contribute to a better understanding of the genetic structure of the core collection as well as to its improvement and validation.

Gill-Langarica, Homar R.; Muruaga-Martinez, Jose S.; Vargas-Vazquez, M.L. Patricia; Rosales-Serna, Rigoberto; Mayek-Perez, Netzahualcoyotl

2011-01-01

58

Application of resistance gene analog markers to analyses of genetic structure and diversity in rice.  

PubMed

Plant disease resistance gene analog (RGA) markers were designed according to the conserved sequence of known RGAs and used to map resistance genes. We used genome-wide RGA markers for genetic analyses of structure and diversity in a global rice germplasm collection. Of the 472 RGA markers, 138 were polymorphic and these were applied to 178 entries selected from the USDA rice core collection. Results from the RGA markers were similar between two methods, UPGMA and STRUCTURE. Additionally, the results from RGA markers in our study were agreeable with those previously reported from SSR markers, including cluster of ancestral classification, genetic diversity estimates, genetic relatedness, and cluster of geographic origins. These results suggest that RGA markers are applicable for analyses of genetic structure and diversity in rice. However, unlike SSR markers, the RGA markers failed to differentiate temperate japonica, tropical japonica, and aromatic subgroups. The restricted way for developing RGA markers from the cDNA sequence might limit the polymorphism of RGA markers in the genome, thus limiting the discriminatory power in comparison with SSR markers. Genetic differentiation obtained using RGA markers may be useful for defining genetic diversity of a suite of random R genes in plants, as many studies show a differentiation of resistance to a wide array of pathogens. They could also help to characterize the genetic structure and geographic distribution in crops, including rice, wheat, barley, and banana. PMID:24099390

Ren, Juansheng; Yu, Yuchao; Gao, Fangyuan; Zeng, Lihua; Lu, Xianjun; Wu, Xianting; Yan, Wengui; Ren, Guangjun

2013-09-06

59

Plant protoplasts as genetic tool: selectable markers for developmental studies.  

PubMed

Protoplasts have usually been presented as a methodological tool. Even as such, they make possible an impressive array of applications in plant biology. Here we report on the use of protoplast-derived selectable markers in the study of several disturbed genetic systems with obvious effects on plant development: (1) auxotrophic mutants and the control of amino acid biosynthesis and transport in vegetative and reproductive tissues; (2) introgression of alien genetic information across phylogenetic boundaries by protoplast fusion, a consequence of controlled dedifferentiation-redifferentiation processes and attenuated incompatibility reactions in cultured cells; (3) expression (in)stability of foreign genes in transgenic plants during successive meiotic generations and in crosses between independent transformants. PMID:1627478

Negrutiu, I; Hinnisdaels, S; Cammaerts, D; Cherdshewasart, W; Gharti-Chhetri, G; Jacobs, M

1992-03-01

60

A Parallel Genetic Algorithm to Discover Patterns in Genetic Markers that Indicate Predisposition to Multifactorial Disease  

PubMed Central

This paper describes a novel algorithm to analyze genetic linkage data using pattern recognition techniques and genetic algorithms (GA). The method allows a search for regions of the chromosome that may contain genetic variations that jointly predispose individuals for a particular disease. The method uses correlation analysis, filtering theory and genetic algorithms (GA) to achieve this goal. Because current genome scans use from hundreds to hundreds of thousands of markers, two versions of the method have been implemented. The first is an exhaustive analysis version that can be used to visualize, explore, and analyze small genetic data sets for two marker correlations; the second is a GA version, which uses a parallel implementation allowing searches of higher-order correlations in large data sets. Results on simulated data sets indicate that the method can be informative in the identification of major disease loci and gene-gene interactions in genome-wide linkage data and that further exploration of these techniques is justified. The results presented for both variants of the method show that it can help genetic epidemiologists to identify promising combinations of genetic factors that might predispose to complex disorders. In particular, the correlation analysis of IBD expression patterns might hint to possible gene-gene interactions and the filtering might be a fruitful approach to distinguish true correlation signals from noise.

Rausch, Tobias; Thomas, Alun; Camp, Nicola J.; Cannon-Albright, Lisa A.; Facelli, Julio C.

2008-01-01

61

Genetic diversity in Hemileia vastatrix based on RAPD markers.  

PubMed

Random amplified polymorphic DNA (RAPD) was used to assess the genetic structure of Hemileia vastatrix populations. Forty-five rust isolates with different virulence spectra and from different hosts and geographical regions were analyzed. Out of 45 bands, generated with three RAPD primers, 35 (78%) were polymorphic and scored as molecular markers. Cluster analysis exhibits unstructured variability of this pathogen with regard to physiological race, geographical origin or host. The genotypic diversity (H') inferred from Shannon's index was higher than gene diversity (Ht), suggesting that diversity is distributed among clonal lineages. Estimates of gene diversity in Africa and Asia populations were higher in total (Ht) as compared to within population diversity (Hs). Genetic differentiation was considerable among coffee rust isolates from Africa (Gst = 0.865) and Asia (Gst = 0.768) but not among isolates from South America (Gst = 0.266). We concluded that genetic diversity in H. vastatrix was moderately low and that the genetic differentiation among populations shows that asexual reproduction is likely to play an important role in the population biology of this fungus. This should be taken into account for the development of breeding programs. PMID:16396347

Gouveia, M Manuela C; Ribeiro, Ana; Várzea, Vítor M P; Rodrigues, Carlos J

62

Genetic variability of watermelon accessions based on microsatellite markers.  

PubMed

We analyzed the genetic variability of 40 watermelon accessions collected from 8 regions of Northeastern Brazil using microsatellite markers, in order to suggest strategies of conservation and utilization of genetic variability in this species. These accessions are not commercial cultivars. They were sampled in areas of traditional farmers that usually keep their own seeds for future plantings year after year. An UPGMA dendrogram was generated from a distance matrix of the Jaccard coefficient, based on 41 alleles of 13 microsatellite loci. Analysis of molecular variance was made by partitioning between and within geographical regions. The similarity coefficient between accessions ranged from 37 to 96%; the dendrogram gave a co-phenetic value of 0.80. The among population genetic variability was high ( (^)?ST = 0.319). Specific clusters of accessions sampled in 3 regions of Maranhão were observed while the other 5 regions did not presented specific clusters by regions. We conclude that watermelon genetic variability is not uniformly dispersed in the regions analyzed, indicating that geographical barriers or edaphoclimatic conditions have limited open mating. We suggest sampling a greater number of populations, so regional species diversity will be better represented and preserved in the germplasm bank. PMID:23546958

de S Gama, R N C; Santos, C A F; de C S Dias, R

2013-03-13

63

Development of Amplified Fragment Length Polymorphism (AFLP) Markers Suitable for Genetic Linkage Mapping of Catfish  

Microsoft Academic Search

Genomic research requires many molecular markers for construction of the genetic linkage map and for marker-assisted selection (MAS). Amplified fragment length polymorphism (AFLP) markers are inherited with Mendelian expectations in catfish and, thus, are suitable for use in gene mapping and MAS. To identify large numbers of AFLP markers, 64 primer combinations were tested to generate AFLP patterns between channel

Zhanjiang Liu; Ping Li; Huseyin Kucuktas; Amy Nichols; Guo Tan; Xinmin Zheng; Brad J. Argue; Rex A. Dunham; D. Roger Yant

1999-01-01

64

Comparative genomic hybridizations of Entamoeba strains reveal unique genetic fingerprints that correlate with virulence.  

PubMed

Variable phenotypes have been identified for Entamoeba species. Entamoeba histolytica is invasive and causes colitis and liver abscesses but only in approximately 10% of infected individuals; 90% remain asymptomatically colonized. Entamoeba dispar, a closely related species, is avirulent. To determine the extent of genetic diversity among Entamoeba isolates and potential genotype-phenotype correlations, we have developed an E. histolytica genomic DNA microarray and used it to genotype strains of E. histolytica and E. dispar. On the basis of the identification of divergent genetic loci, all strains had unique genetic fingerprints. Comparison of divergent genetic regions allowed us to distinguish between E. histolytica and E. dispar, identify novel genetic regions usable for strain and species typing, and identify a number of genes restricted to virulent strains. Among the four E. histolytica strains, a strain with attenuated virulence was the most divergent and phylogenetically distinct strain, raising the intriguing possibility that genetic subtypes of E. histolytica may be partially responsible for the observed variability in clinical outcomes. This microarray-based genotyping assay can readily be applied to the study of E. histolytica clinical isolates to determine genetic diversity and potential genotypic-phenotypic associations. PMID:15755913

Shah, Preetam H; MacFarlane, Ryan C; Bhattacharya, Dhruva; Matese, John C; Demeter, Janos; Stroup, Suzanne E; Singh, Upinder

2005-03-01

65

Psychological aspects of human cloning and genetic manipulation: the identity and uniqueness of human beings.  

PubMed

Human cloning has become one of the most controversial debates about reproduction in Western civilization. Human cloning represents asexual reproduction, but the critics of human cloning argue that the result of cloning is not a new individual who is genetically unique. There is also awareness in the scientific community, including the medical community, that human cloning and the creation of clones are inevitable. Psychology and other social sciences, together with the natural sciences, will need to find ways to help the healthcare system, to be prepared to face the new challenges introduced by the techniques of human cloning. One of those challenges is to help the healthcare system to find specific standards of behaviour that could be used to help potential parents to interact properly with cloned babies or children created through genetic manipulation. In this paper, the concepts of personality, identity and uniqueness are discussed in relationship to the contribution of twin studies in these areas. The author argues that an individual created by human cloning techniques or any other type of genetic manipulation will not show the donor's characteristics to the extent of compromising uniqueness. Therefore, claims to such an effect are needlessly alarmist. PMID:19891847

Morales, N M

2009-01-01

66

A unique specification method for processed unicorn filefish products using a DNA barcode marker  

Microsoft Academic Search

The present study evaluated and compared the utility of the cytochrome b and cytochrome c oxidase I genes as mitochondrial markers for determining the original species and for food regulatory control. Evaluation of a selected DNA barcode region, using a newly designed species-specific primer set, generated a species-specific ‘fingerprint’, and tested the efficacy of this barcode during analysis of simulated

Ya-Chen Yang; Yao-Wen Huang; Cheng-Hong Hsieh; Yu-Ru Huang; Chien-Hung Chen

67

Identification of genetic markers to distinguish the virulent and avirulent subspecies of Pantoea stewartii by comparative proteomics and genetic analysis.  

PubMed

Pantoea stewartii subsp. stewartii (Pnss), the causal agent of Stewart's bacterial wilt and leaf blight of maize and sweet corn, is one of the quarantine pathogens in many countries and regions. In contrast, P. stewartii subsp. indologenes (Pnsi), the closely related subspecies of Pnss, is avirulent on these plants. In this study, the protein expression profiles of these two subspecies were compared using two-dimensional gel electrophoresis analysis. Twenty-one unique protein spots consistently detected in Pnss but not in Pnsi were analyzed by mass spectrometry. Some of these Pnss-specific proteins are known to be essential for virulence and survival in host, such as FoxR and HrcJ, which are the key components of iron uptake and Type III secretion systems, respectively. For further genetic analysis, six Pnss-specific proteins were characterized by peptide sequencing. Southern and Northern blot analyses revealed that the differences in protein expression profiles of the two subspecies were either due to the discrepancy at genome level or because of the variations in transcriptional expression. The results provide novel genetic markers to distinguish the two closely related subspecies and may also serve as useful clues for investigation of the genetic basis accounting for their sharp difference in virulence. PMID:17086414

Wu, Qiong; Jiang, Zide; Liao, Jinliang; Chen, Zhinan; Li, Huaping; Mei, Mantong; Zhang, Lian-Hui

2006-11-04

68

Estimating quantitative genetic parameters using sibships reconstructed from marker data.  

PubMed Central

Previous techniques for estimating quantitative genetic parameters, such as heritability in populations where exact relationships are unknown but are instead inferred from marker genotypes, have used data from individuals on a pairwise level only. At this level, families are weighted according to the number of pairs within which each family appears, hence by size rather than information content, and information from multiple relationships is lost. Estimates of parameters are therefore not the most efficient achievable. Here, Markov chain Monte Carlo techniques have been used to partition the population into complete sibships, including, if known, prior knowledge of the distribution of family sizes. These pedigrees have then been used with restricted maximum likelihood under an animal model to estimate quantitative genetic parameters. Simulations to compare the properties of parameter estimates with those of existing techniques indicate that the use of sibship reconstruction is superior to earlier methods, having lower mean square errors and showing nonsignificant downward bias. In addition, sibship reconstruction allows the estimation of population allele frequencies that account for the relationships within the sample, so prior knowledge of allele frequencies need not be assumed. Extensions to these techniques allow reconstruction of half sibships when some or all of the maternal genotypes are known.

Thomas, S C; Hill, W G

2000-01-01

69

Detection of common vetch (Vicia sativa L.) in Lentil (Lens culinaris L.) using unique chemical fingerprint markers.  

PubMed

Detection of adulteration of split red lentil (Lens culinaris L.) seeds with low level addition of split common vetch (Vicia sativa L.) is hampered by a lack of reliable detection methods. An analytical method was developed using high performance liquid chromatography with diode array detection (HPLC-DAD) based on two unique chemical markers found in common vetch: ß-cyanoalanine (BCA) and ?-glutamyl-ß-cyanoalanine (GCA). These two markers were present in samples of common vetch seed grown in Canada and Serbia. Authentic lentil samples grown in Canada, Australia, USA, Turkey, Syria, and Morocco had no detectable levels of these chemical markers. Commercial lentil samples for export from lentil processing plants in Saskatchewan, Canada, also had no detectable levels of GCA and BCA. The presence of vetch in intentionally adulterated lentil samples could be determined via chemical markers with a detection limit of 5% (w/w). The proposed method is a simple sample extraction and rapid HPLC analysis that could be widely used to detect intentional adulteration of lentils with common vetch. PMID:22980791

Thavarajah, Pushparajah; Thavarajah, Dil; Premakumara, G A S; Vandenberg, Albert

2012-07-14

70

Genome-wide genetic marker discovery and genotyping using next-generation sequencing  

Microsoft Academic Search

The advent of next-generation sequencing (NGS) has revolutionized genomic and transcriptomic approaches to biology. These new sequencing tools are also valuable for the discovery, validation and assessment of genetic markers in populations. Here we review and discuss best practices for several NGS methods for genome-wide genetic marker development and genotyping that use restriction enzyme digestion of target genomes to reduce

Paul A. Hohenlohe; Paul D. Etter; Jason Q. Boone; Julian M. Catchen; Mark L. Blaxter; John W. Davey

2011-01-01

71

Diverse Genetic Markers Concordantly Identify Bovine Origin Escherichia coli O157 Genotypes Underrepresented in Human Disease? †  

PubMed Central

Genetic markers previously reported to occur at significantly different frequencies in isolates of Escherichia coli O157:H7 obtained from cattle and from clinically affected humans concordantly delineate at least five genetic groups. Isolates in three of these groups consistently carry one or more markers rarely found among clinical isolates.

Whitworth, Joshua; Zhang, Yubei; Bono, James; Pleydell, Eve; French, Nigel; Besser, Thomas

2010-01-01

72

Comparative Analysis of Genetic Diversity and Structure in Rice Using ILP and SSR Markers  

Microsoft Academic Search

Genetic diversity of 36 rice entries from the United States Department of Agriculture (USDA) rice collection was assessed using 103 ILP (intron length polymorphism) and 54 SSR (simple sequence repeats) markers. A total of 236 and 332 alleles were detected by the ILP and SSR markers, respectively. On average, the SSR markers produced higher polymorphism information content value and number

Ming HUANG; Fang-min XIE; Li-yun CHEN; Xiang-qian ZHAO; L. JOJEE; D. MADONNA

2010-01-01

73

MLVA and SNP analysis identified a unique genetic cluster in Bulgarian Bacillus anthracis strains.  

PubMed

A collection of 40 Bacillus anthracis strains mostly isolated from soil in Bulgaria between 1960 and 1980 were investigated. All strains were proven to be B. anthracis by culture and amplification of a B. anthracis-specific chromosomal marker. PCR demonstrated that in nine strains both virulence plasmids (pX01+/pX02+) and in four strains only one plasmid (pX02+) were present, whereas the majority of strains (n = 27) lacked both plasmids (pX01-/pX02-). Multi-locus-variable number of tandem repeat-analysis (MLVA) using 15 markers differentiated three genotypes. Comparison with typing data of more than 1,000 different B. anthracis strains revealed that Bulgarian genotypes affiliated with the A1.a cluster and form their own unique cluster different from clusters containing strains isolated in geographical proximity, e.g., Turkey, Georgia, Hungary, Albania or Italy. In addition, a new allele of one marker (vrrC2) was identified. Canonical single nucleotide polymorphisms analysis allocated 31 Bulgarian strains into the A.Br.008/009 and nine strains into the A.Br.WNA group, which is the first description of B. anthracis strains of the A.Br.WNA group on the Eurasian continent. PMID:21279731

Antwerpen, M; Ilin, D; Georgieva, E; Meyer, H; Savov, E; Frangoulidis, D

2011-01-30

74

Reproductive Meristem22 is a unique marker for the early stages of stamen development.  

PubMed

Stamens undergo a very elaborate development program that gives rise not only to many specific tissue types, but also to the male gametes. The specification of stamen identity is coordinated by a group of homeotic genes such as APETALA3 (AP3) and PISTILLATA (PI), AGAMOUS (AG) and SEPALLATA (SEP1-4) genes. Genome-wide transcriptomic comparisons between floral buds of wild-type and ap3 mutants led to the identification of the REM22 gene, which is expressed in the early stages of stamen development. This gene is member of the plant-specific B3 DNA-binding superfamily. In this work, we dissect the spatio-temporal expression pattern of REM22 during the early stages of stamen development. To this end, both in situ hybridization analyses as well as in vivo fluorescence strategies were employed. At stage 4 of flower development, REM22 is expressed exclusively in those undifferentiated cells of the floral meristem that will give rise to the stamen primordia. At stage 5, REM22 expression is restricted to the epidermal and the subepidermal layers of anther primordia. Later, this expression is confined to the middle layer and the differentiating tapetal cells. After stage 10 when all the tissues of the anther have differentiated, REM22 expression is no longer detectable. Furthermore, we examined the pREM22::GUS-GFP marker line in an inducible system where the ectopic AG function is used to promote microsporogenesis. The data support the idea that REM22 expression is a useful marker to study the early stages of stamen development. PMID:21948714

Romanel, Elisson; Das, Pradeep; Amasino, Richard M; Traas, Jan; Meyerowitz, Elliot; Alves-Ferreira, Marcio

2011-01-01

75

Alu repeats as markers for human population genetics  

SciTech Connect

The Human-Specific (HS) subfamily of Alu sequences is comprised of a group of 500 nearly identical members which are almost exclusively restricted to the human genome. Individual subfamily members share an average of 97.9% nucleotide identity with each other and an average of 98.9% nucleotide identity with the HS subfamily consensus sequence. HS Alu family members are thought to be derived from a single source ``master`` gene, and have an average age of 2.8 million years. We have developed a Polymerase Chain Reaction (PCR) based assay using primers complementary to the 5 in. and 3 in. unique flanking DNA sequences from each HS Alu that allows the locus to be assayed for the presence or absence of an Alu repeat. Individual HS Alu sequences were found to be either monomorphic or dimorphic for the presence or absence of each repeat. The monomorphic HS Alu family members inserted in the human genome after the human/great ape divergence (which is thought to have occurred 4--6 million years ago), but before the radiation of modem man. The dimorphic HS Alu sequences inserted in the human genome after the radiation of modem man (within the last 200,000-one million years) and represent a unique source of information for human population genetics and forensic DNA analyses. These sites can be developed into Dimorphic Alu Sequence Tagged Sites (DASTS) for the Human Genome Project as well. HS Alu family member insertion dimorphism differs from other types of polymorphism (e.g. Variable Number of Tandem Repeat [VNTR] or Restriction Fragment Length Polymorphism [RFLP]) because individuals share HS Alu family member insertions based upon identity by descent from a common ancestor as a result of a single event which occurred one time within the human population. The VNTR and RFLP polymorphisms may arise multiple times within a population and are identical by state only.

Batzer, M.A.; Alegria-Hartman, M. [Lawrence Livermore National Lab., CA (United States); Bazan, H. [Louisiana State Univ., New Orleans, LA (United States). Medical Center] [and others

1993-09-01

76

Assessment of genetic variation within Indian mustard (Brassica juncea) germplasm using random amplified polymorphic DNA markers.  

PubMed

Genetic diversity among 45 Indian mustard (Brassica juncea L.) genotypes comprising 37 germplasm collections, five advance breeding lines and three improved cultivars was investigated at the DNA level using the random amplified polymorphic DNA (RAPD) technique. Fifteen primers used generated a total of 92 RAPD fragments, of which 81 (88%) were polymorphic. Of these, 13 were unique to accession 'Pak85559'. Each primer produced four to nine amplified products with an average of 6.13 bands per primer. Based on pairwise comparisons of RAPD amplification products, Nei and Li's similarity coefficients were calculated to evaluate the relationships among the accessions. Pairwise similarity indices were higher among the oilseed accessions and cultivars showing narrow ranges of 0.77-0.99. An unweighted pair-group method with arithmetic averages cluster analysis based on these genetic similarities placed most of the collections and oilseed cultivars close to each other, showing a low level of polymorphism between the accessions used. However, the clusters formed by oilseed collections and cultivars were comparatively distinct from that of advanced breeding lines. Genetically, all of the accessions were classified into a few major groups and a number of individual accessions. Advanced breeding lines were relatively divergent from the rest of the accessions and formed independent clusters. Clustering of the accessions did not show any pattern of association between the RAPD markers and the collection sites. A low level of genetic variability of oilseed mustard was attributed to the selection for similar traits and horticultural uses. Perhaps close parentage of these accessions further contributed towards their little diversity. The study demonstrated that RAPD is a simple and fast technique to compare the genetic relationship and pattern of variation among the gene pool of this crop. PMID:18713372

Khan, Muhammad Ayub; Rabbani, Malik Ashiq; Munir, Muhammad; Ajmal, Saifullah Khan; Malik, Muhammad Azim

2008-04-01

77

Epigenetic-Genetic Chromosome Dosage Approach for Fetal Trisomy 21 Detection Using an Autosomal Genetic Reference Marker  

Microsoft Academic Search

BackgroundThe putative promoter of the holocarboxylase synthetase (HLCS) gene on chromosome 21 is hypermethylated in placental tissues and could be detected as a fetal-specific DNA marker in maternal plasma. Detection of fetal trisomy 21 (T21) has been demonstrated by an epigenetic-genetic chromosome dosage approach where the amount of hypermethylated HLCS in maternal plasma is normalized using a fetal genetic marker

Yu K. Tong; Rossa W. K. Chiu; Ranjit Akolekar; Tak Y. Leung; Tze K. Lau; Kypros H. Nicolaides; Y. M. Dennis Lo; Roland G. Roberts

2010-01-01

78

Genetic diversity and relationships among Lablab purpureus genotypes evaluated using RAPD as markers  

Microsoft Academic Search

Genetic variation in 40 accessions of Lablab purpureus was evaluated using random amplified polymorphic DNA as markers. A high level of genetic variation in this species was detected but this was mainly restricted to the difference between cultivated and wild forms. Of the cultivated genotypes, genetic variation among Asian collections was significantly higher than that among African collections. The three

C. J. Liu

1996-01-01

79

DEVELOPMENT OF GENETIC MARKERS FOR STRIPED BASS (MORONE SAXITILIS) AND RAINBOW TROUT (ONCORHYNCHUS MYKISS)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The NCCCWA is developing molecular genetic markers to aid in the genetic improvement of cool and cold water species for aquaculture production efficiency. Through the construction of genetic maps, we aim to identify quantitative trait loci (QTL) harboring genes having large affects on economically ...

80

Estimation of genetic marker effects for CAPN1, CAST, and GHR on carcass quality traits in Angus cattle selected to increase minor marker frequencies  

Technology Transfer Automated Retrieval System (TEKTRAN)

Genetic marker effects and interactions cannot be accurately estimated when minor marker allele frequencies (MAF) are low. To increase the accuracy of estimation for three marker systems in commercial use, an Angus population at USMARC was subjected to marker assisted-selection for multiple years t...

81

A Unique Cyanide Adduct in Human Serum Albumin - Potential as a Surrogate Exposure Marker  

PubMed Central

Cyanide (CN = HCN + CN?) is a renowned poison and neurotoxicant that is prevalent throughout the environment. Despite a plethora of studies conducted over the last half century, relatively little is known of its potential to cause adverse health outcomes at sublethal exposures. CN exposure is normally determined from blood, but because CN is rapidly metabolized and cleared from this compartment (t1/2 < 1 h), it is common for several half-lives to have passed before blood samples are drawn for analysis. This variable, coupled with a very narrow toxic index and metabolic diversity within the human population, have rendered accurate assessment of CN exposure, and consequently any predictions of possible adverse health outcomes, highly problematic. Prior studies by us showed the potential of Cys-SCN adducts within human serum albumin (HSA) to act as retrospective surrogates of CN exposure. Here we report the discovery of a stable, SCN adduct at Cys567 formed by reaction of CN with the C-terminal Cys558Cys567 disulfide bond of HSA. Treatment of HSA purified from human serum with base in guanidine hydrochloride releases a readily detectable, uniquely modified, C-terminal-19 mer peptide from Cys567-SCN moieties in all the samples examined thus far. Inclusion of a HSA-Cys567-S13C15N labeled internal standard permits quantitation of the Cys567- SCN adduct by LC-MS/MS in Selective Reaction Monitoring (SRM) of the surrogate peptide with high sensitivity and good precision. Reaction of CN in vitro with the Cys558Cys567 disulfide bond in HSA is specific, rapid, and concentration dependent within a putative, physiologically-relevant range. Data from various human sera demonstrate the potential usefulness of this adduct as a biomarker of CN exposure.

Fasco, Michael J.; Stack, Robert F.; Lu, Shijun; Hauer, Charles R.; Schneider, Erasmus; Dailey, Michael; Aldous, Kenneth M.

2011-01-01

82

Impact of Marker Ascertainment Bias on Genomic Selection Accuracy and Estimates of Genetic Diversity  

PubMed Central

Genome-wide molecular markers are often being used to evaluate genetic diversity in germplasm collections and for making genomic selections in breeding programs. To accurately predict phenotypes and assay genetic diversity, molecular markers should assay a representative sample of the polymorphisms in the population under study. Ascertainment bias arises when marker data is not obtained from a random sample of the polymorphisms in the population of interest. Genotyping-by-sequencing (GBS) is rapidly emerging as a low-cost genotyping platform, even for the large, complex, and polyploid wheat (Triticum aestivum L.) genome. With GBS, marker discovery and genotyping occur simultaneously, resulting in minimal ascertainment bias. The previous platform of choice for whole-genome genotyping in many species such as wheat was DArT (Diversity Array Technology) and has formed the basis of most of our knowledge about cereals genetic diversity. This study compared GBS and DArT marker platforms for measuring genetic diversity and genomic selection (GS) accuracy in elite U.S. soft winter wheat. From a set of 365 breeding lines, 38,412 single nucleotide polymorphism GBS markers were discovered and genotyped. The GBS SNPs gave a higher GS accuracy than 1,544 DArT markers on the same lines, despite 43.9% missing data. Using a bootstrap approach, we observed significantly more clustering of markers and ascertainment bias with DArT relative to GBS. The minor allele frequency distribution of GBS markers had a deficit of rare variants compared to DArT markers. Despite the ascertainment bias of the DArT markers, GS accuracy for three traits out of four was not significantly different when an equal number of markers were used for each platform. This suggests that the gain in accuracy observed using GBS compared to DArT markers was mainly due to a large increase in the number of markers available for the analysis.

Heslot, Nicolas; Rutkoski, Jessica; Poland, Jesse; Jannink, Jean-Luc; Sorrells, Mark E.

2013-01-01

83

Construction of a genetic linkage map for cultivated peanut and development of QTLs/markers for marker-assisted breeding  

Technology Transfer Automated Retrieval System (TEKTRAN)

Several genetic maps based on recombinant inbred line (RIL) and backcross (BC) populations have been developed for tetraploid peanut recently. The marker density, however, is still very low especially in context of large genome size (2,800Mb/1C) and 20 linkage groups (LGs). Therefore, improvement of...

84

Intra-specific genetic relationship analyses of Elaeagnus angustifolia based on RP-HPLC biochemical markers.  

PubMed

Elaeagnus angustifolia Linn. has various ecological, medicinal and economical uses. An approach was established using RP-HPLC (reversed-phase high-performance liquid chromatography) to classify and analyse the intra-specific genetic relationships of seventeen populations of E. angustifolia, collected from the Xinjiang areas of China. Chromatograms of alcohol-soluble proteins produced by seventeen populations of E. angustifolia, were compared. Each chromatogram of alcohol-soluble proteins came from a single seed of one wild plant only. The results showed that when using a Waters Delta Pak. C18, 5 microm particle size reversed phase column (150 mm x 3.9 mm), a linear gradient of 25%-60% solvent B with flow rate of 1 ml/min and run time of 67 min, the chromatography yielded optimum separation of E. angustifolia alcohol-soluble proteins. Representative peaks in each population were chosen according to peak area and occurrence in every seed. The converted data on the elution peaks of each population were different and could be used to represent those populations. GSC (genetic similarity coefficients) of 41% to 62% showed a medium degree of genetic diversity among the populations in these eco-areas. Cluster analysis showed that the seventeen populations of E. angustifolia could be divided into six clusters at the GSC=0.535 level and indicated the general and unique biochemical markers of these clusters. We suggest that E. angustifolia distribution in these eco-areas could be classified into six variable species. RP-HPLC was shown to be a rapid, repeatable and reliable method for E. angustifolia classification and identification and for analysis of genetic diversity. PMID:16532528

Wang, Qiang; Ruan, Xiao; Huang, Jun-hua; Xu, Ning-yi; Yan, Qi-chuan

2006-04-01

85

Construction of a rat genetic map by using randomly amplified microsatellite polymorphism (RAMP) markers  

Microsoft Academic Search

.   Many rat strains have been employed in the genetic study of quantitative traits such as blood pressure. In such genetic studies,\\u000a it is essential to prepare rat genetic maps fine enough to identify the genes regulating quantitative traits. However, it\\u000a is not an easy task to isolate a sufficient number of genetic markers polymorphic between a particular pair of

Chiho Matsumoto; Toru Nabika; Tomoji Mashimo; Norihiro Kato; Yukio Yamori; Junichi Masuda

1998-01-01

86

[Searching for genetic markers--in the fields of forensic medicine and human genetics].  

PubMed

Research on genetic markers in the fields of forensic medicine and human genetics did not begin in earnest until 1968. Study of an extended family in Wakayama Prefecture resulted in the discovery of the variant Bm type in the ABO blood group system. This family of nearly 40 members composed of Group A, B, O and AB spouses and type Bm monozygotic twins provided the best research material possible. An extremely rare case of an individual with type O red blood cells but no anti-A or anti-B antibodies led to the discovery of type AmBm. Fishman and Mitsuhashi advocated the concept of immunogenetic RNA. We attempted to examine the immunogenetic RNA function by isolating RNA from the human spleen but obtained no definitive results. Many researchers had since examined the genetic markers in erythrocytes, leukocytes, serum proteins and blood cell enzymes, but research on genetic marker in saliva had not been advanced. We searched for genetic markers in the parotid saliva and developed the PmF and Ph systems. A salivary amylase variant and acid phosphatase polymorphism were also discovered. We elucidated the genetic structure and geographic gradinet of the salivary genetic markers, such as the Pa, Pb, Pr, Db and PIF systems, in Japanese. The genetic markers in the tear and saliva of mice and rats were also detected. We demonstrated RFLP polymorphism using an amylase cDNA probe. Our report was one of the first on polymorphism in the field of forensic medicine in Japan. Interest was also directed to polymorphism in platelet and we employed two-dimensional electrophoresis to establish the ThA and ThB systems which are controlled by autosomal codominant genes. Regarding the research on monoclonal antibody production and their application in forensic medicine, we cloned and produced antibodies for ABO, MN and Lewis grouping. Anti-glycopholin-A, anti-glycopholin-B and anti-glycolipid monoclonal antibodies were also produced and used to divide the red blood cell antigens roughly into three classes; the glycopholin-A (MN), glycopholin-B (Ss. Duffy Kell-Cellano, Lutheran, Diego, Xg) and the glycolipid (ABO, Lewis, P) classes. Red blood cell protein membrane proteases were also isolated from Nepenthes alata extract and lectin which are used in grouping animal blood cells. In the research on erythrocyte differentiation and erythrocyte group substance expression, we established a selective two phase liquid culture system for culturing precursor cells of peripheral erythrocytes, and demonstrated the expression of red blood cell antigens such as ABO, Rh and Duffy antigens in the early period (4 to 9 days) of Phase 2. Recently, research on identifying the genes which code for polymorphism in erythrocytes or erythrocyte enzymes is making progress. For example, a study indicated a possible relationship between an isoform of the glycophorin A gene and the MN variant. In the cDNA sequence of the Fy (a-b+) and (a + b-) types in the Duffy system, a GAT (Asp) to GGT (Gly) substitution in the codon for residual 44 was detected. Research on the Rh gene is being pursued energetically. Two clones of the Rh gene have been isolated; Rh Pl composed of 1251 bases, and Rh Pll estimated to be Ph PI with a base substitution at position 41 and an amino acid substitution at position 31. Seven isoforms of Ph Pl and 5 isoforms of Ph Pll have been obtained. The delineation of the Rh gene which contains as many as 50 types of Rh antigen genes is in progress. The red blood cell enzyme EsD system is also used commonly in the field of forensic genetics. In EsD polymorphism, type EsD1 contains G at base 569, type EsD2 contains A and type EsD1-2 shows a heterologous conjugation of G and A. Due to the development of immunosuppressive agents, bone marrow transplant can now be conducted even when the ABO and Rh systems are not compatible, as long as the HLA is compatible. In this case, all the erythrocyte polymorphic types or erythrocyte enzyme polymorphic types are transformed to t PMID:8583686

Ikemoto, S

1995-12-01

87

Population genetic study of Fagopyrum tataricum from Western Himalaya using ISSR markers.  

PubMed

Inter-simple sequence repeat (ISSR) markers were used to analyze genetic diversity and relatedness of 15 germplasms of Fagopyrum tataricum. Samples representing 75 individuals were collected from a range of altitudes in the Western Himalaya. The 13 ISSR primers revealed 98.1% polymorphism among populations, whereas average polymorphism was extremely low (2.18%) within populations. The coefficient of population differentiation was 0.9750, with limited gene flow (N m) of 0.0128. The average PIC value of the ISSR markers was high (0.812), with a marker ratio of 0.65 and marker index of 6.66. The genetic diversity of F. tataricum significantly correlated with altitude and gene diversity, Shannon's index, and the percentage of polymorphic bands. The genetic diversity among populations showed broad genetic base and provided a developmental strategy for crop improvement. PMID:23743875

Kishore, Garima; Pandey, Anjana; Dobhal, Rajendra; Gupta, Sanjay

2013-06-07

88

Progress in cellular engineering of plants: biochemical and genetic assessment of selectable markers from cultured cells  

Microsoft Academic Search

Recent availability of stable and well characterized selectable markers and ability to combine alien genomes parasexually have contributed to the development of molecular biology in higher plants, including gene expression and genetic manipulation.

Ioan Negrutiu; Michel Jacobs; Arlette Cattoir-Reynaerts

1984-01-01

89

Characterization of Breast Cancer Progression by Analysis of Genetic Markers.  

National Technical Information Service (NTIS)

Genetic changes implicated in the etiology of breast cancer have been identified by the detection of loss of heterozygosity at specific loci. Our study utilizes a series of genetic polymorphisms detectable by the polymerase chain reaction (PCR) to look fo...

J. Lichy

1995-01-01

90

Genotypic diversity, molecular markers and spatial distribution of genets in clonal plants, a literature survey  

Microsoft Academic Search

We present a literature survey of studies using molecular markers to investigate genet diversity and structure in clonal plants.\\u000a The data from 40 studies comprised 45 species of which only two were studied by DNA methods, the rest by isozyme markers.\\u000a Less than one third of the studies provided information about the spatial distribution of individual genets within populations,\\u000a and

Björn Widén; Nils Cronberg; Marie Widén

1994-01-01

91

Genetic Divergence Detected by ISSR Markers and Characterization of Microsatellite Regions in Mytilus Mussels  

Microsoft Academic Search

The wide distribution of microsatellites in mussels of the Mytilus edulis complex (Mytilidae) enables the analysis of inter-simple-sequence repeat (ISSR) markers. The aim of this investigation was\\u000a to assess genetic differentiation in six sampling localities distributed along the European Atlantic coast to expose the potential\\u000a of these markers in genetic studies requiring the detection of low polymorphism and as a

Miguel A. Varela; Ana González-Tizón; Luis Mariñas; Andrés Martínez-Lage

2007-01-01

92

Functional markers for gene mapping and genetic diversity studies in sugarcane  

Microsoft Academic Search

Background  The database of sugarcane expressed sequence tags (EST) offers a great opportunity for developing molecular markers that are\\u000a directly associated with important agronomic traits. The development of new EST-SSR markers represents an important tool for\\u000a genetic analysis. In sugarcane breeding programs, functional markers can be used to accelerate the process and select important\\u000a agronomic traits, especially in the mapping of

Thiago G Marconi; Estela A Costa; Hercília RCAN Miranda; Melina C Mancini; Cláudio B Cardoso-Silva; Karine M Oliveira; Luciana R Pinto; Marcelo Mollinari; Antônio AF Garcia; Anete P Souza

2011-01-01

93

Estimating Heritabilities and Genetic Correlations with Marker-Based Methods: An Experimental Test in Mimulus guttatus  

Microsoft Academic Search

The calculation of heritabilities and genetic correlations, which are necessary for predicting evolutionary responses, requires knowledge about the relatedness between individuals. This information is often not directly available, especially not for natural populations, but can be inferred by using molecular markers such as allozymes. Several methods based on inferred relatedness from marker data have been developed to estimate heritabilities and

M. van Kleunen; K. RITLAND

2005-01-01

94

Genetic diversity of mango cultivars estimated using Start Codon Targeted (SCoT) markers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diversity and genetic relationships among 23 mango germplasm accessions, collected from different locations in Guangxi province in China, were analyzed by using a novel and simple gene targeted DNA marker: Start Codon Targeted (SCoT) markers. This technique uses a single, 18-mer primer PCR amplifica...

95

Genetic Linkage Maps of the Guppy ( Poecilia reticulata ): Assignment of RAPD Markers to Multipoint Linkage Groups  

Microsoft Academic Search

Genetic linkage maps of the guppy ( Poecilia reticulata) were constructed from independent crosses between the Tuxedo strain and a feral line (Wildtype). Segregation patterns of random amplified polymorphic DNA (RAPD) markers and phenotypic markers were investigated in F 2 offspring of Tuxedo ?? × Wildtype ?? and Wildtype ?? × Tuxedo ?? crosses. Among the 300 and 276 RAPD

Gideon Khoo; Meng Huat Lim; Haridas Suresh; Damien K. Y. Gan; Kok Fang Lim; Fan Chen; Woon-Khiong Chan; Tit Meng Lim; Violet P. E. Phang

2003-01-01

96

Isolation, characterization, and development of WRKY genes as useful genetic markers in Theobroma cacao  

Microsoft Academic Search

There is currently an international effort in improving disease resistance and crop yield in Theobroma cacao L., an economically important crop of the tropics, using marker-assisted selection for breeding. We are developing molecular genetic markers focusing upon gene families involved with disease resistance. One such family is the WRKY proteins, which are plant-specific transcriptional factors associated with regulating defense responses

James W. Borrone; David N. Kuhn; Raymond J. Schnell

2004-01-01

97

A review on SNP and other types of molecular markers and their use in animal genetics  

Microsoft Academic Search

During the last ten years, the use of molecular markers, revealing polymorphism at the DNA level, has been playing an increasing part in animal genetics studies. Amongst others, the microsatellite DNA marker has been the most widely used, due to its easy use by simple PCR, followed by a denaturing gel electrophoresis for allele size determination, and to the high

Alain Vignal; Denis Milan; Magali SanCristobal; André Eggen

2002-01-01

98

Assessment of natural and induced genetic variation in Alstroemeria using random amplified polymorphic DNA (RAPD) markers  

Microsoft Academic Search

We have used random amplified polymorphic DNA (RAPD) markers to study genetic variation in Alstroemeria. The first objective was to examine the discriminatory power of RAPD markers in different genotypes of Alstroemeria obtained by traditional breeding. All genotypes examined, including commercial Alstroemeria varieties, could be distinguished on the basis of their RAPD profiles. Progeny plants could be distinguished from their

E. Anastassopoulos; M. Keil

1996-01-01

99

Cystic Fibrosis Locus Defined by a Genetically Linked Polymorphic DNA Marker  

Microsoft Academic Search

A polymorphic DNA marker has been found genetically linked, in a set of 39 human families, to an autosomal recessive gene that causes cystic fibrosis (CF), a disease affecting one in 2000 Caucasian children. The DNA marker (called D0CRI-917) is also linked to the PON locus, which by independent evidence is linked to the CF locus. The best estimates of

Lap-Chee Tsui; Manuel Buchwald; David Barker; Jeffrey C. Braman; Robert Knowlton; James W. Schumm; Hans Eiberg; Jan Mohr; Dara Kennedy; Natasa Plavsic; Martha Zsiga; Danuta Markiewicz; Gita Akots; Valerie Brown; Cynthia Helms; Thomas Gravius; Carol Parker; Kenneth Rediker; Helen Donis-Keller

1985-01-01

100

SIMPLE SEQUENCE REPPEAT (SSR) MARKERS FOR GENETIC MAPPING OF RASPBERRY AND BLACKBERRY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Interest in molecular markers and genetic maps is growing among researchers developing new cultivars of Rubus L. (raspberry and blackberry). Several traits of interest fail to express in seedlings or in all environments and are candidates for marker-assisted selection. A growing number of simple seq...

101

The selectable marker human dihydrofolate reductase enables sequential genetic manipulation of the Plasmodium berghei genome  

Microsoft Academic Search

Genetic transformation of malaria parasites has been limited by the number of selectable markers available. For the rodent malaria parasite, Plasmodium berghei, only a single selection marker has been at hand, utilising the dihydrofolate reductase-thymidylate synthase gene from either P. berghei or Toxoplasma gondii to confer resistance to the anti-malarial drug pyrimethamine. Here we report the use of the human

Tania F. de Koning-Ward; David A. Fidock; Vandana Thathy; Robert Menard; Rosalina M. L. van Spaendonk; Andrew P. Waters; Chris J. Janse

2000-01-01

102

Transcriptome sequencing of field pea and faba bean for discovery and validation of SSR genetic markers  

PubMed Central

Background Field pea (Pisum sativum L.) and faba bean (Vicia faba L.) are cool-season grain legume species that provide rich sources of food for humans and fodder for livestock. To date, both species have been relative 'genomic orphans' due to limited availability of genetic and genomic information. A significant enrichment of genomic resources is consequently required in order to understand the genetic architecture of important agronomic traits, and to support germplasm enhancement, genetic diversity, population structure and demographic studies. Results cDNA samples obtained from various tissue types of specific field pea and faba bean genotypes were sequenced using 454 Roche GS FLX Titanium technology. A total of 720,324 and 304,680 reads for field pea and faba bean, respectively, were de novo assembled to generate sets of 70,682 and 60,440 unigenes. Consensus sequences were compared against the genome of the model legume species Medicago truncatula Gaertn., as well as that of the more distantly related, but better-characterised genome of Arabidopsis thaliana L.. In comparison to M. truncatula coding sequences, 11,737 and 10,179 unique hits were obtained from field pea and faba bean. Totals of 22,057 field pea and 18,052 faba bean unigenes were subsequently annotated from GenBank. Comparison to the genome of soybean (Glycine max L.) resulted in 19,451 unique hits for field pea and 16,497 unique hits for faba bean, corresponding to c. 35% and 30% of the known gene space, respectively. Simple sequence repeat (SSR)-containing expressed sequence tags (ESTs) were identified from consensus sequences, and totals of 2,397 and 802 primer pairs were designed for field pea and faba bean. Subsets of 96 EST-SSR markers were screened for validation across modest panels of field pea and faba bean cultivars, as well as related non-domesticated species. For field pea, 86 primer pairs successfully obtained amplification products from one or more template genotypes, of which 59% revealed polymorphism between 6 genotypes. In the case of faba bean, 81 primer pairs displayed successful amplification, of which 48% detected polymorphism. Conclusions The generation of EST datasets for field pea and faba bean has permitted effective unigene identification and functional sequence annotation. EST-SSR loci were detected at incidences of 14-17%, permitting design of comprehensive sets of primer pairs. The subsets from these primer pairs proved highly useful for polymorphism detection within Pisum and Vicia germplasm.

2012-01-01

103

Distribution of Genetic Marker Concentrations for Fecal Indicator Bacteria in Sewage and Animal Feces  

PubMed Central

Very little is known about the density and distribution of fecal indicator bacteria (FIB) genetic markers measured by quantitative real-time PCR (qPCR) in fecal pollution sources. Before qPCR-based FIB technologies can be applied to waste management and public health risk applications, it is vital to characterize the concentrations of these genetic markers in pollution sources (i.e., untreated wastewater and animal feces). We report the distribution of rRNA genetic markers for several general FIB groups, including Clostridium spp., Escherichia coli, enterococci, and Bacteroidales, as determined by qPCR on reference collections consisting of 54 primary influent sewage samples collected from treatment facilities across the United States and fecal samples representing 20 different animal species. Based on raw sewage sample collection data, individual FIB genetic markers exhibited a remarkable similarity in concentration estimates from locations across the United States ranging from Hawaii to Florida. However, there was no significant correlation between genetic markers for most FIB combinations (P > 0.05). In addition, large differences (up to 5 log10 copies) in the abundance of FIB genetic markers were observed between animal species, emphasizing the importance of indicator microorganism selection and animal source contribution for future FIB applications.

Kelty, Catherine A.; Varma, Manju; Sivaganesan, Mano; Haugland, Richard A.

2012-01-01

104

The Application and Performance of Single Nucleotide Polymorphism Markers for Population Genetic Analyses of Lepidoptera  

PubMed Central

Microsatellite markers are difficult to apply within lepidopteran studies due to the lack of locus-specific PCR amplification and the high proportion of “null” alleles, such that erroneous estimations of population genetic parameters often result. Herein single nucleotide polymorphism (SNP) markers are developed from Ostrinia nubilalis (Lepidoptera: Crambidae) using next generation expressed sequence tag (EST) data. A total of 2742 SNPs were predicted within a reference assembly of 7414 EST contigs, and a subset of 763 were incorporated into 24 multiplex PCR reactions. To validate this pipeline, 5 European and North American sample sites were genotyped at 178 SNP loci, which indicated 84 (47.2%) were in Hardy–Weinberg equilibrium. Locus-by-locus FST, analysis of molecular variance, and STRUCTURE analyses indicate significant genetic differentiation may exist between European and North American O. nubilalis. The observed genetic diversity was significantly lower among European sites, which may result from genetic drift, natural selection, a genetic bottleneck, or ascertainment bias due to North American origin of EST sequence data. SNPs are an abundant source of mutation data for molecular genetic marker development in non-model species, with shared ancestral SNPs showing application within closely related species. These markers offer advantages over microsatellite markers for genetic and genomic analyses of Lepidoptera, but the source of mutation data may affect the estimation of population parameters and likely need to be considered in the interpretation of empirical data.

Coates, Brad Steven; Bayles, Darrell O.; Wanner, Kevin W.; Robertson, Hugh M.; Hellmich, Richard L.; Sappington, Thomas W.

2011-01-01

105

Development and characterization of highly polymorphic long TC repeat microsatellite markers for genetic analysis of peanut  

PubMed Central

Background Peanut (Arachis hypogaea L.) is a crop of economic and social importance, mainly in tropical areas, and developing countries. Its molecular breeding has been hindered by a shortage of polymorphic genetic markers due to a very narrow genetic base. Microsatellites (SSRs) are markers of choice in peanut because they are co-dominant, highly transferrable between species and easily applicable in the allotetraploid genome. In spite of substantial effort over the last few years by a number of research groups, the number of SSRs that are polymorphic for A. hypogaea is still limiting for routine application, creating the demand for the discovery of more markers polymorphic within cultivated germplasm. Findings A plasmid genomic library enriched for TC/AG repeats was constructed and 1401 clones sequenced. From the sequences obtained 146 primer pairs flanking mostly TC microsatellites were developed. The average number of repeat motifs amplified was 23. These 146 markers were characterized on 22 genotypes of cultivated peanut. In total 78 of the markers were polymorphic within cultivated germplasm. Most of those 78 markers were highly informative with an average of 5.4 alleles per locus being amplified. Average gene diversity index (GD) was 0.6, and 66 markers showed a GD of more than 0.5. Genetic relationship analysis was performed and corroborated the current taxonomical classification of A. hypogaea subspecies and varieties. Conclusions The microsatellite markers described here are a useful resource for genetics and genomics in Arachis. In particular, the 66 markers that are highly polymorphic in cultivated peanut are a significant step towards routine genetic mapping and marker-assisted selection for the crop.

2012-01-01

106

A consensus genetic map of sorghum that integrates multiple component maps and high-throughput Diversity Array Technology (DArT) markers  

PubMed Central

Background Sorghum genome mapping based on DNA markers began in the early 1990s and numerous genetic linkage maps of sorghum have been published in the last decade, based initially on RFLP markers with more recent maps including AFLPs and SSRs and very recently, Diversity Array Technology (DArT) markers. It is essential to integrate the rapidly growing body of genetic linkage data produced through DArT with the multiple genetic linkage maps for sorghum generated through other marker technologies. Here, we report on the colinearity of six independent sorghum component maps and on the integration of these component maps into a single reference resource that contains commonly utilized SSRs, AFLPs, and high-throughput DArT markers. Results The six component maps were constructed using the MultiPoint software. The lengths of the resulting maps varied between 910 and 1528 cM. The order of the 498 markers that segregated in more than one population was highly consistent between the six individual mapping data sets. The framework consensus map was constructed using a "Neighbours" approach and contained 251 integrated bridge markers on the 10 sorghum chromosomes spanning 1355.4 cM with an average density of one marker every 5.4 cM, and were used for the projection of the remaining markers. In total, the sorghum consensus map consisted of a total of 1997 markers mapped to 2029 unique loci (1190 DArT loci and 839 other loci) spanning 1603.5 cM and with an average marker density of 1 marker/0.79 cM. In addition, 35 multicopy markers were identified. On average, each chromosome on the consensus map contained 203 markers of which 58.6% were DArT markers. Non-random patterns of DNA marker distribution were observed, with some clear marker-dense regions and some marker-rare regions. Conclusion The final consensus map has allowed us to map a larger number of markers than possible in any individual map, to obtain a more complete coverage of the sorghum genome and to fill a number of gaps on individual maps. In addition to overall general consistency of marker order across individual component maps, good agreement in overall distances between common marker pairs across the component maps used in this study was determined, using a difference ratio calculation. The obtained consensus map can be used as a reference resource for genetic studies in different genetic backgrounds, in addition to providing a framework for transferring genetic information between different marker technologies and for integrating DArT markers with other genomic resources. DArT markers represent an affordable, high throughput marker system with great utility in molecular breeding programs, especially in crops such as sorghum where SNP arrays are not publicly available.

Mace, Emma S; Rami, Jean-Francois; Bouchet, Sophie; Klein, Patricia E; Klein, Robert R; Kilian, Andrzej; Wenzl, Peter; Xia, Ling; Halloran, Kirsten; Jordan, David R

2009-01-01

107

Retene Emission from Residential Solid Fuels in China and Evaluation of Retene as a Unique Marker for Soft Wood Combustion  

PubMed Central

Retene (1-methyl-7-isopropylphenanthrene) is often used as a marker for softwood combustion and for polycyclic aromatic hydrocarbon (PAH) source apportionment. The emission factors of retene (EFRET) from 11 crop residues, 27 firewood and 5 coals were measured using traditional rural Chinese stoves. Retene was measured in combustion emissions from all of the residential fuels tested and EFRET varied significantly among the fuels due to the differences in fuel properties and combustion conditions. EFRET for pine (0.34±0.08 mg/kg) and larch (0.29±0.22 mg/kg) were significantly higher than those of other wood types, including fir and cypress (0.081±0.058 mg/kg). However, EFRET for crop residues varied from 0.048±0.008 to 0.37±0.14 mg/kg and were not significantly lower than those for softwood (0.074±0.026 to 0.34±0.08 mg/kg). The EFRET for coal were very high and ranged from 2.2±1.5 (anthracite briquette) to 187±113 mg/kg (raw bituminous chunk). EFRET was positively correlated with EFs of co-emitted particulate matter (EFPM) and phenanthrene (EFPHE) for crop residue and coal, but not for wood. In addition, the ratios of EFPHE/EFRET and EFPM/EFRET for coals were much lower than those for crop residues and wood. These data suggest that retene is not a unique PAH marker for softwood combustion and that coal combustion, in particular, should be taken into account when retene is used for PAH source apportionment.

Shen, Guofeng; Tao, Shu; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Yang, Yifeng; Wang, Wei; Wang, Xilong; Massey Simonich, Staci L.

2012-01-01

108

Collecting Duct Carcinomas Represent a Unique Tumor Entity Based on Genetic Alterations  

PubMed Central

Collecting duct carcinoma (CDC) is a rare renal neoplasm that is associated with poor prognosis due to its highly aggressive course and limited response to immuno- or chemotherapy. Histologically, CDC is defined as a subtype of renal cell carcinomas, but in some cases, it is difficult to differentiate from urothelial carcinomas (UC). Therefore the aim of this study was to determine genetic alterations of CDC in comparison to that of urothelial carcinomas of the upper urinary tract (UUT-UC) to clarify the histological origin of this rare tumor entity. Twenty-nine CDC samples were obtained from seven different German centers and compared with twenty-six urothelial carcinomas of the upper urinary tract. Comparative genomic hybridization (CGH) was used to investigate the genetic composition of patients’ tumors and allowed the detection of losses and gains of DNA copy numbers throughout the entire genome. The clinical data were correlated with CGH results. CGH analysis of CDC revealed DNA aberrations in many chromosomes. DNA losses were more frequently observed than gains, while high-level amplifications were not detected. The mean frequency of CDC chromosomal aberrations (4.9/case) was slightly lower than that in UUT-UC (5.4/case). Recurrent CDC DNA losses occurred at 8p (n=9/29), 16p (9/29), 1p (n=7/29) and 9p (n=7/29), and gains occurred in 13q (n=9/29). In contrast to CDC, the most frequently detected UUT-UC DNA aberration was a loss at 9q (n=13/26). DNA losses at 9q, 13q and 8q as well as gains at 8p showed significant variations in UUT-UC compared to CDC. There was no correlation between the patients’ clinical course and the presence or absence of these recurrent genetic alterations. CDCs are characterized by a different genetic pattern compared to UUT-UC. Regarding the published data on renal cell carcinoma, we conclude that CDC appears to be a unique entity among kidney carcinomas.

Parr, Martin; Hartmann, Arndt; Fussel, Susanne; Toma, Marieta; Grobholz, Rainer; Pflugmann, Thomas; Wullich, Bernd; Strauss, Arne; Behnes, Carl Ludwig; Otto, Wolfgang; Stockle, Michael; Jung, Volker

2013-01-01

109

An annotated genetic map of loblolly pine based on microsatellite and cDNA markers  

PubMed Central

Background Previous loblolly pine (Pinus taeda L.) genetic linkage maps have been based on a variety of DNA polymorphisms, such as AFLPs, RAPDs, RFLPs, and ESTPs, but only a few SSRs (simple sequence repeats), also known as simple tandem repeats or microsatellites, have been mapped in P. taeda. The objective of this study was to integrate a large set of SSR markers from a variety of sources and published cDNA markers into a composite P. taeda genetic map constructed from two reference mapping pedigrees. A dense genetic map that incorporates SSR loci will benefit complete pine genome sequencing, pine population genetics studies, and pine breeding programs. Careful marker annotation using a variety of references further enhances the utility of the integrated SSR map. Results The updated P. taeda genetic map, with an estimated genome coverage of 1,515 cM(Kosambi) across 12 linkage groups, incorporated 170 new SSR markers and 290 previously reported SSR, RFLP, and ESTP markers. The average marker interval was 3.1 cM. Of 233 mapped SSR loci, 84 were from cDNA-derived sequences (EST-SSRs) and 149 were from non-transcribed genomic sequences (genomic-SSRs). Of all 311 mapped cDNA-derived markers, 77% were associated with NCBI Pta UniGene clusters, 67% with RefSeq proteins, and 62% with functional Gene Ontology (GO) terms. Duplicate (i.e., redundant accessory) and paralogous markers were tentatively identified by evaluating marker sequences by their UniGene cluster IDs, clone IDs, and relative map positions. The average gene diversity, He, among polymorphic SSR loci, including those that were not mapped, was 0.43 for 94 EST-SSRs and 0.72 for 83 genomic-SSRs. The genetic map can be viewed and queried at http://www.conifergdb.org/pinemap. Conclusions Many polymorphic and genetically mapped SSR markers are now available for use in P. taeda population genetics, studies of adaptive traits, and various germplasm management applications. Annotating mapped genes with UniGene clusters and GO terms allowed assessment of redundant and paralogous EST markers and further improved the quality and utility of the genetic map for P. taeda.

2011-01-01

110

Genetic marker anchoring by six-dimensional pools for development of a soybean physical map  

Technology Transfer Automated Retrieval System (TEKTRAN)

Integrated genetic and physical maps are extremely valuable for genomic studies and as important references for assembling of whole genome shotgun sequences. Screening of a BAC library using molecular markers is an indispensable procedure for integration of both physical and genetic maps of a genom...

111

Genetic diversity of bitter gourd ( Momordica charantia L.) genotypes revealed by RAPD markers and agronomic traits  

Microsoft Academic Search

Bitter gourd or bitter melon (Momordica charantia L.) is considered as minor cucurbitaceous vegetable in spite of having considerable nutritional and medicinal properties. Although some reports on genetic diversity based on morphological characterization are available, no work has been conducted to estimate genetic diversity using molecular markers in this crop. In the present study, 38 genotypes of M. charantia including

S. S. Dey; A. K. Singh; D. Chandel; T. K. Behera

2006-01-01

112

Genetic Diversity and Molecular Markers in Introduced and Thai Native Apple Snails (Pomacea and Pila)  

Microsoft Academic Search

The genetic diversity and species-diagnostic markers in the introduced apple snail, Pomacea canaliculata and in the native Thai apple snails; Pila ampullacea, P. angelica, P. pesmei, and P. polita, were investigated by restriction analysis of COI and are reported for the first time. Twenty- one composite haplotypes showing non-overlapping distributions among species were found. Genetic heterogeneity analysis indicated significant differences

Bungorn Thaewnon-ngiw; Sirawut Klinbunga; Nitsri Sangduen; Nitaya Lauhachinda; Piamsak Menasveta

2004-01-01

113

New microsatellite markers for assessment of genetic diversity in date palm (Phoenix dactylifera L.).  

PubMed

New primer pairs of genomic DNA microsatellite markers were tested to assess the genetic diversity of eleven date palm genotypes. The results indicated that out of thirty, only seven primers (23.3%) failed to amplify the expected PCR fragments, while thirteen primers (43.3%) amplified monomorphic banding patterns and the remaining ten primers (33.4%) generated polymorphic banding patterns. A total of 77 alleles have been observed with a mean of 7.7 alleles per locus. The average of gene diversity was 0.80 ranging from 0.6 (in marker DP168) to 0.9 (in two markers DP157 and DP175). These new co-dominant markers will be a starting point for researchers making use of the markers for genetic mapping and diversity analysis of date palm. PMID:22582150

Elmeer, Khaled; Sarwath, Hina; Malek, Joel; Baum, Michael; Hamwieh, Aladdin

2011-05-27

114

Development of microsatellite markers from an enriched genomic library for genetic analysis of melon (Cucumis melo L.)  

Microsoft Academic Search

BACKGROUND: Despite the great advances in genomic technology observed in several crop species, the availability of molecular tools such as microsatellite markers has been limited in melon (Cucumis melo L.) and cucurbit species. The development of microsatellite markers will have a major impact on genetic analysis and breeding of melon, especially on the generation of marker saturated genetic maps and

Patricia Silva Ritschel; Tulio Cesar de Lima Lins; Rodrigo Lourenço Tristan; Gláucia Salles Cortopassi Buso; José Amauri Buso; Márcio Ferreira

2004-01-01

115

Genetic diversity in wild species of passion fruit (Passiflora trintae) based on molecular markers.  

PubMed

In spite of the importance of and the considerable variability observed in Passiflora (Passifloraceae), little is known about the genetic diversity of most of the species of this genus. We evaluated the genetic diversity by RAPD markers in 18 genotypes of Passiflora trintae. The 15 primers generated 112 markers, 84% of which were polymorphic. The genetic distance estimated by the complement of the Dice index (average dissimilarity = 0.30) and genotype grouping based on the UPGMA algorithm showed low variability among genotypes. More attention should be given to the study and conservation of the biodiversity of this economically important genus. PMID:21038298

Cerqueira-Silva, C B M; Cardoso-Silva, C B; Santos, E S L; Conceição, L D H C S; Pereira, A S; Oliveira, A C; Corrêa, R X

2010-10-26

116

Genetic Diversity in Algerian Sheep Breeds, Using Microsatellite Markers  

Microsoft Academic Search

Two breeds — Ouled-Djellal and Hamra (85 animals) — were genotyped for 12 microsatellites using PCR and sequencing. Allele number and frequency were calculated, and 141 different alleles were found for these microsatellites, reflecting high genetic variability within these breeds. This study is being extended to other Algerian breeds to estimate variability and genetic distances between them. In parallel, blood

Souheil Gaouar; Nacera Tabet-Aoul; Amal Derrar; Kathayoun Goudarzy-Moazami; Nadhira Saïdi-Mehtar

117

Genetic diversity of a Coffea Germplasm Collection assessed by RAPD markers  

Microsoft Academic Search

Genetic diversity and relationships within and among nine species of Coffea, one species of Psilanthus and the Piatã hybrid from the Coffee Germplasm Collection of Instituto Agronômico de Campinas (IAC), Brazil were assessed\\u000a using RAPD markers. Genetic diversity and relationships were evaluated by proportion of polymorphic loci (P), Shannon’s genetic index (H? and G?ST) and clustering analysis. The overall RAPD

Milene Silvestrini; Mirian P. Maluf; Maria B. Silvarolla; Oliveiro Guerreiro-Filho; Herculano P. Medina-Filho; Marina M. T. Vanini; Adalgisa S. Oliveira; Cristiana de Gaspari-Pezzopane; Luiz C. Fazuoli

2008-01-01

118

Methods of analysis for 2-dodecylcyclobutanone and studies to support its role as a unique marker of food irradiation.  

PubMed

Methods of analysis for 2-dodecylcyclobutanone (2-DCB) using gas chromatography with mass spectrometric detection (GC-MS), liquid chromatography with time-of-flight mass spectrometric detection (LC-TOF-MS) and LC with tandem MS (MS/MS) detection have been developed and optimised for maximum sensitivity to allow very low irradiation doses to be detected. The LC-MS/MS method, following derivatisation with 2,4-dinitrophenylhydrazine, was found to be the most sensitive technique and was used to determine the amount of 2-DCB formed from the model compounds palmitic acid, glyceryl tripalmitate and 1,3-dipalmitoyl-2-oleoylglycerol irradiated over a range of doses by two different irradiation sources (gamma and electron beam). The model compounds were also treated with a number of non-irradiation based processing techniques including heating in the presence and absence of oxygen, light, and redox active metal salts, in a conventional oven, microwave oven and pressure cooker. No 2-DCB was detected in any of the processed non-irradiated model compounds, reaffirming the hypothesis that 2-DCB is a unique radiolytic product that can be used as a marker of irradiation in foodstuffs. PMID:24176347

Driffield, M; Speck, D; Lloyd, A S; Parmar, M; Crews, C; Castle, L; Thomas, C

2013-09-18

119

Genetic diversity in cultivated carioca common beans based on molecular marker analysis  

PubMed Central

A wide array of molecular markers has been used to investigate the genetic diversity among common bean species. However, the best combination of markers for studying such diversity among common bean cultivars has yet to be determined. Few reports have examined the genetic diversity of the carioca bean, commercially one of the most important common beans in Brazil. In this study, we examined the usefulness of two molecular marker systems (simple sequence repeats – SSRs and amplified fragment length polymorphisms – AFLPs) for assessing the genetic diversity of carioca beans. The amount of information provided by Roger’s modified genetic distance was used to analyze SSR data and Jaccards similarity coefficient was used for AFLP data. Seventy SSRs were polymorphic and 20 AFLP primer combinations produced 635 polymorphic bands. Molecular analysis showed that carioca genotypes were quite diverse. AFLPs revealed greater genetic differentiation and variation within the carioca genotypes (Gst = 98% and Fst = 0.83, respectively) than SSRs and provided better resolution for clustering the carioca genotypes. SSRs and AFLPs were both suitable for assessing the genetic diversity of Brazilian carioca genotypes since the number of markers used in each system provided a low coefficient of variation. However, fingerprint profiles were generated faster with AFLPs, making them a better choice for assessing genetic diversity in the carioca germplasm.

Kupper Cardoso Perseguini, Juliana Morini; Chioratto, Alisson Fernando; Zucchi, Maria Imaculada; Colombo, Carlos Augusto; Carbonell, Sergio Augusto Moraes; Costa Mondego, Jorge Mauricio; Gazaffi, Rodrigo; Franco Garcia, Antonio Augusto; de Campos, Tatiana; de Souza, Anete Pereira; Rubiano, Luciana Benchimol

2011-01-01

120

A unique genetic and biochemical presentation of fish-eye disease.  

PubMed Central

This paper describes a novel genetic defect which causes fish-eye disease in four homozygous probands and its biochemical presentation in 34 heterozygous siblings. The male index patient presented with premature coronary artery disease, corneal opacification, HDL deficiency, and a near total loss of plasma lecithin:cholesterol acyltransferase (LCAT) activity. Sequencing of the LCAT gene revealed homozygosity for a novel missense mutation resulting in an Asp131 - Asn (N131D) substitution. Heterozygotes showed a highly significant reduction of HDL-cholesterol and apolipoprotein A-I levels as compared with controls which was associated with a specific decrease of LpA-I:A-II particles. Functional assessment of this mutation revealed loss of specific activity of recombinant LCAT(N131D) against proteoliposomes. Unlike other mutations causing fish-eye disease, recombinant LCAT(N131D) also showed a 75% reduction in specific activity against LDL. These unique biochemical characteristics reveal the heterogeneity of phenotypic expression of LCAT gene defects within a range specified by complete loss of LCAT activity and the specific loss of activity against HDL. The impact of this mutation on HDL levels and HDL subclass distribution may be related to the premature coronary artery disease observed in the male probands. Images

Kuivenhoven, J A; van Voorst tot Voorst, E J; Wiebusch, H; Marcovina, S M; Funke, H; Assmann, G; Pritchard, P H; Kastelein, J J

1995-01-01

121

Population Genetic Effects of Urban Habitat Fragmentation in the Perennial Herb Viola pubescens (Violaceae) using ISSR Markers  

PubMed Central

Background and Aims Fragmentation of natural habitats can negatively impact plant populations by leading to reduced genetic variation and increased genetic distance as populations become geographically and genetically isolated from one another. To test whether such detrimental effects occur within an urban landscape, the genetic structure of six populations of the perennial herb Viola pubescens was characterized in the metropolitan area of Greater Cincinnati in southwestern Ohio, USA. Methods Using three inter-simple sequence repeat (ISSR) markers, 51 loci amplified across all urban populations. For reference, four previously examined agricultural populations in central/northern Ohio and a geographically distant population in Michigan were also included in the analysis. Key Results Urban populations retained high levels of genetic variation (percentage of polymorphic loci, Pp = 80·7 %) with similar genetic distances among populations and an absence of unique alleles. Geographic and genetic distances were correlated with one another, and all populations grouped according to region. Individuals from urban populations clustered together and away from individuals from agricultural populations and from the Michigan population in a principle coordinates analysis. Hierarchical analysis of molecular variance (AMOVA) revealed that most of the genetic variability was partitioned within populations (69·1 %) and among groups (22·2 %) of southwestern Ohio, central/northern Ohio and Michigan groups. Mean Fst was 0·308, indicating substantial population differentiation. Conclusions It is concluded that urban fragmentation does not appear to impede gene flow in V. pubescens in southwestern Ohio. These results are consistent with life history traits of this species and the possibility of high insect abundance in urban habitats due to diverse floral resources and nesting sites. Combined with the cleistogamous breeding system of this species, pollinator availability in the urban matrix may buffer populations against detrimental effects of habitat fragmentation, at least in larger forest fragments. Consequently, it may be inappropriate to generalize about genetic effects of fragmentation across landscapes or even across plant species with different pollination systems.

Culley, Theresa M.; Sbita, Sarah J.; Wick, Anne

2007-01-01

122

Construction of a 10,000-Marker Ultradense Genetic Recombination Map of Potato: Providing a Framework for Accelerated Gene Isolation and a Genomewide Physical Map  

PubMed Central

An ultradense genetic linkage map with >10,000 AFLP loci was constructed from a heterozygous diploid potato population. To our knowledge, this is the densest meiotic recombination map ever constructed. A fast marker-ordering algorithm was used, based on the minimization of the total number of recombination events within a given marker order in combination with genotyping error-detection software. This resulted in “skeleton bin maps,” which can be viewed as the most parsimonious marker order. The unit of distance is not expressed in centimorgans but in “bins.” A bin is a position on the genetic map with a unique segregation pattern that is separated from adjacent bins by a single recombination event. Putative centromeres were identified by a strong clustering of markers, probably due to cold spots for recombination. Conversely, recombination hot spots resulted in large intervals of up to 15 cM without markers. The current level of marker saturation suggests that marker density is proportional to physical distance and independent of recombination frequency. Most chromatids (92%) recombined once or never, suggesting strong chiasma interference. Absolute chiasma interference within a chromosome arm could not be demonstrated. Two examples of contig construction and map-based cloning have demonstrated that the marker spacing was in accordance with the expected physical distance: approximately one marker per BAC length. Currently, the markers are used for genetic anchoring of a physical map of potato to deliver a sequence-ready minimal tiling path of BAC contigs of specific chromosomal regions for the potato genome sequencing consortium (http://www.potatogenome.net).

van Os, Hans; Andrzejewski, Sandra; Bakker, Erin; Barrena, Imanol; Bryan, Glenn J.; Caromel, Bernard; Ghareeb, Bilal; Isidore, Edwige; de Jong, Walter; van Koert, Paul; Lefebvre, Veronique; Milbourne, Dan; Ritter, Enrique; van der Voort, Jeroen N. A. M. Rouppe; Rousselle-Bourgeois, Francoise; van Vliet, Joke; Waugh, Robbie; Visser, Richard G. F.; Bakker, Jaap; van Eck, Herman J.

2006-01-01

123

Genetic Diversity Revealed by Single Nucleotide Polymorphism Markers in a Worldwide Germplasm Collection of Durum Wheat  

PubMed Central

Evaluation of genetic diversity and genetic structure in crops has important implications for plant breeding programs and the conservation of genetic resources. Newly developed single nucleotide polymorphism (SNP) markers are effective in detecting genetic diversity. In the present study, a worldwide durum wheat collection consisting of 150 accessions was used. Genetic diversity and genetic structure were investigated using 946 polymorphic SNP markers covering the whole genome of tetraploid wheat. Genetic structure was greatly impacted by multiple factors, such as environmental conditions, breeding methods reflected by release periods of varieties, and gene flows via human activities. A loss of genetic diversity was observed from landraces and old cultivars to the modern cultivars released during periods of the Early Green Revolution, but an increase in cultivars released during the Post Green Revolution. Furthermore, a comparative analysis of genetic diversity among the 10 mega ecogeographical regions indicated that South America, North America, and Europe possessed the richest genetic variability, while the Middle East showed moderate levels of genetic diversity.

Ren, Jing; Sun, Daokun; Chen, Liang; You, Frank M.; Wang, Jirui; Peng, Yunliang; Nevo, Eviatar; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua

2013-01-01

124

Genetic diversity revealed by single nucleotide polymorphism markers in a worldwide germplasm collection of durum wheat.  

PubMed

Evaluation of genetic diversity and genetic structure in crops has important implications for plant breeding programs and the conservation of genetic resources. Newly developed single nucleotide polymorphism (SNP) markers are effective in detecting genetic diversity. In the present study, a worldwide durum wheat collection consisting of 150 accessions was used. Genetic diversity and genetic structure were investigated using 946 polymorphic SNP markers covering the whole genome of tetraploid wheat. Genetic structure was greatly impacted by multiple factors, such as environmental conditions, breeding methods reflected by release periods of varieties, and gene flows via human activities. A loss of genetic diversity was observed from landraces and old cultivars to the modern cultivars released during periods of the Early Green Revolution, but an increase in cultivars released during the Post Green Revolution. Furthermore, a comparative analysis of genetic diversity among the 10 mega ecogeographical regions indicated that South America, North America, and Europe possessed the richest genetic variability, while the Middle East showed moderate levels of genetic diversity. PMID:23538839

Ren, Jing; Sun, Daokun; Chen, Liang; You, Frank M; Wang, Jirui; Peng, Yunliang; Nevo, Eviatar; Sun, Dongfa; Luo, Ming-Cheng; Peng, Junhua

2013-03-28

125

The origin of the Japanese race based on genetic markers of immunoglobulin G  

PubMed Central

This review addresses the distribution of genetic markers of immunoglobulin G (Gm) among 130 Mongoloid populations in the world. These markers allowed the populations to be clearly divided into 2 groups, the northern and southern groups. The northern group is characterized by high frequencies of 2 marker genes, ag and ab3st, and an extremely low frequency of the marker gene afb1b3; and the southern group, in contrast, is indicated by a remarkably high frequency of afb1b3 and low frequencies of ag and ab3st. Based on the geographical distribution of the markers and gene flow of Gm ag and ab3st (northern Mongoloid marker genes) from northeast Asia to the Japanese archipelago, the Japanese population belongs basically to the northern Mongoloid group and is thus suggested to have originated in northeast Asia, most likely in the Baikal area of Siberia.

Matsumoto, Hideo

2009-01-01

126

The use of genetic markers to measure genomic response to selection in livestock.  

PubMed Central

A method to measure genomic response to natural and artificial selection by means of genetic markers in livestock is proposed. Genomic response through several levels of selection was measured using sequential testing for distorted segregation of alleles among selected and nonselected sons, single-sperm typing, and a test with records for growth performance. Statistical power at a significance level of 0.05 was >0.5 for a marker linked to a QTL with recombination fractions 0, 0.10, and 0.20 for detecting genomic responses for gene effects of 0.6, 0.7, and 1.0 phenotypic standard deviations, respectively. Genomic response to artificial selection in six commercial bull sire families comprising 285 half-sib sons selected for growth performance was measured using 282 genetic markers evenly distributed over the cattle genome. A genome-wide test using selected sons was significant (P < 0.001), indicating that selection induces changes in the genetic makeup of commercial cattle populations. Markers located in chromosomes 6, 10, and 16 identified regions in those chromosomes that are changing due to artificial selection as revealed by the association of records of performance with alleles at specific markers. Either natural selection or genetic drift may cause the observed genomic response for markers in chromosomes 1, 7, and 17.

Gomez-Raya, Luis; Olsen, Hanne Gro; Lingaas, Frode; Klungland, Helge; Vage, Dag Inge; Olsaker, Ingrid; Talle, Seblewengel Bekele; Aasland, Monica; Lien, Sigbj?rn

2002-01-01

127

A genetic linkage map of quinoa ( Chenopodium quinoa) based on AFLP, RAPD, and SSR markers.  

PubMed

Quinoa ( Chenopodium quinoa Willd.) is an important seed crop for human consumption in the Andean region of South America. It is the primary staple in areas too arid or saline for the major cereal crops. The objective of this project was to build the first genetic linkage map of quinoa. Selection of the mapping population was based on a preliminary genetic similarity analysis of four potential mapping parents. Breeding lines 'Ku-2' and '0654', a Chilean lowland type and a Peruvian Altiplano type, respectively, showed a low similarity coefficient of 0.31 and were selected to form an F(2) mapping population. The genetic map is based on 80 F(2) individuals from this population and consists of 230 amplified length polymorphism (AFLP), 19 simple-sequence repeat (SSR), and six randomly amplified polymorphic DNA markers. The map spans 1,020 cM and contains 35 linkage groups with an average marker density of 4.0 cM per marker. Clustering of AFLP markers was not observed. Additionally, we report the primer sequences and map locations for 19 SSR markers that will be valuable tools for future quinoa genome analysis. This map provides a key starting point for genetic dissection of agronomically important characteristics of quinoa, including seed saponin content, grain yield, maturity, and resistance to disease, frost, and drought. Current efforts are geared towards the generation of more than 200 mapped SSR markers and the development of several recombinant-inbred mapping populations. PMID:15309300

Maughan, P J; Bonifacio, A; Jellen, E N; Stevens, M R; Coleman, C E; Ricks, M; Mason, S L; Jarvis, D E; Gardunia, B W; Fairbanks, D J

2004-08-12

128

Multivariate selection of genetic markers in diagnostic classification  

Microsoft Academic Search

Analysis of gene expression data obtained from microarrays presents a new set of challenges to machine learning modeling. In this domain, in which the number of variables far exceeds the number of cases, identifying relevant genes or groups of genes that are good markers for a particular classification is as important as achieving good classification performance. Although several machine learning

Griffin Weber; Staal A. Vinterbo; Lucila Ohno-machado

2004-01-01

129

Genetic prognostic and predictive markers in colorectal cancer  

Microsoft Academic Search

Despite many studies of the likely survival outcome of individual patients with colorectal cancer, our knowledge of this subject remains poor. Until recently, we had virtually no understanding of individual responses to therapy, but the discovery of the KRAS mutation as a marker of probable failure of epidermal growth factor receptor (EGFR)-targeted therapy is a first step in the tailoring

Axel Walther; Elaine Johnstone; Charles Swanton; Rachel Midgley; Ian Tomlinson; David Kerr

2009-01-01

130

Augmenting the genetic toolbox for Sulfolobus islandicus with a stringent positive selectable marker for agmatine prototrophy.  

PubMed

Sulfolobus species have become the model organisms for studying the unique biology of the crenarchaeal division of the archaeal domain. In particular, Sulfolobus islandicus provides a powerful opportunity to explore natural variation via experimental functional genomics. To support these efforts, we further expanded genetic tools for S. islandicus by developing a stringent positive selection for agmatine prototrophs in strains in which the argD gene, encoding arginine decarboxylase, has been deleted. Strains with deletions in argD were shown to be auxotrophic for agmatine even in nutrient-rich medium, but growth could be restored by either supplementation of exogenous agmatine or reintroduction of a functional copy of the argD gene from S. solfataricus P2 into the ?argD host. Using this stringent selection, a robust targeted gene knockout system was established via an improved next generation of the MID (marker insertion and unmarked target gene deletion) method. Application of this novel system was validated by targeted knockout of the upsEF genes involved in UV-inducible cell aggregation formation. PMID:23835176

Zhang, Changyi; Cooper, Tara E; Krause, David J; Whitaker, Rachel J

2013-07-08

131

Genetic markers of osteoarticular disorders: facts and hopes  

PubMed Central

Osteoarthritis and osteoporosis are the two most common age-related chronic disorders of articular joints and skeleton, representing a major public health problem in most developed countries. Apart from being influenced by environmental factors, both disorders have a strong genetic component, and there is now considerable evidence from large population studies that these two disorders are inversely related. Thus, an accurate analysis of the genetic component of one of these two multifactorial diseases may provide data of interest for the other. However, the existence of confounding factors must always be borne in mind in interpreting the genetic analysis. In addition, each patient must be given an accurate clinical evaluation, including family history, history of drug treatments, lifestyle, and environment, in order to reduce the background bias. Here, we review the impact of recent work in molecular genetics suggesting that powerful molecular biology techniques will soon make possible both a rapid accumulation of data on the genetics of both disorders and the development of novel diagnostic, prognostic, and therapeutic approaches.

Brandi, Maria Luisa; Gennari, Luigi; Cerinic, Marco Matucci; Becherini, Lucia; Falchetti, Alberto; Masi, Laura; Gennari, Carlo; Reginster, Jean-Yves

2001-01-01

132

Inferring Species Trees Directly from Biallelic Genetic Markers: Bypassing Gene Trees in a Full Coalescent Analysis  

PubMed Central

The multispecies coalescent provides an elegant theoretical framework for estimating species trees and species demographics from genetic markers. However, practical applications of the multispecies coalescent model are limited by the need to integrate or sample over all gene trees possible for each genetic marker. Here we describe a polynomial-time algorithm that computes the likelihood of a species tree directly from the markers under a finite-sites model of mutation effectively integrating over all possible gene trees. The method applies to independent (unlinked) biallelic markers such as well-spaced single nucleotide polymorphisms, and we have implemented it in SNAPP, a Markov chain Monte Carlo sampler for inferring species trees, divergence dates, and population sizes. We report results from simulation experiments and from an analysis of 1997 amplified fragment length polymorphism loci in 69 individuals sampled from six species of Ourisia (New Zealand native foxglove).

Bryant, David; Bouckaert, Remco; Felsenstein, Joseph; Rosenberg, Noah A.; RoyChoudhury, Arindam

2012-01-01

133

Identification of genetic markers with synergistic survival effect in cancer  

PubMed Central

Background Cancers are complex diseases arising from accumulated genetic mutations that disrupt intracellular signaling networks. While several predisposing genetic mutations have been found, these individual mutations account only for a small fraction of cancer incidence and mortality. With large-scale measurement technologies, such as single nucleotide polymorphism (SNP) microarrays, it is now possible to identify combinatorial effects that have significant impact on cancer patient survival. Results The identification of synergetic functioning SNPs on genome-scale is a computationally daunting task and requires advanced algorithms. We introduce a novel algorithm, Geninter, to identify SNPs that have synergetic effect on survival of cancer patients. Using a large breast cancer cohort we generate a simulator that allows assessing reliability and accuracy of Geninter and logrank test, which is a standard statistical method to integrate genetic and survival data. Conclusions Our results show that Geninter outperforms the logrank test and is able to identify SNP-pairs with synergetic impact on survival.

2013-01-01

134

Genetic variability in wild genotypes of Passiflora cincinnata based on RAPD markers.  

PubMed

The genetic diversity and characteristics of commercial interest of Passiflora species make it useful to characterize wild germplasm, because of their potential use for fruit, ornamental and medicinal purposes. We evaluated genetic diversity, using RAPD markers, of 32 genotypes of Passiflora cincinnata collected from the wild in the region of Vitória da Conquista, Bahia, Brazil. Thirteen primers generated 95 polymorphic markers and only one monomorphic marker. The mean genetic distance between the genotypes estimated by the complement of the Dice index was 0.51 (ranging from 0.20-0.85), and genotype grouping based on the UPGMA algorithm showed wide variability among the genotypes. This type of information contributes to identification and conservation of the biodiversity of this species and for the identification of pairs of divergent individuals for maximum exploitation of existing variability. PMID:21174261

Cerqueira-Silva, C B M; Conceição, L D H C S; Santos, E S L; Cardoso-Silva, C B; Pereira, A S; Oliveira, A C; Corrêa, R X

2010-12-21

135

Genetic diversity in Lima bean (Phaseolus lunatus L.) as revealed by RAPD markers  

Microsoft Academic Search

The genetic variability of 46 accessions of the Lima bean (P. lunatus L.) including 16 wild forms and 30 landraces belonging\\u000a to the three cultigroups Big lima, Sieva, Potato, and their intermediates, was evaluated using RAPD (Random amplified polymorphic\\u000a DNA) markers. Twelve oligonucleotide primers produced 172 RAPD markers which allowed the differentiation of two main groups:\\u000a the mesoamerican and the

B. Fofana; X. Vekemans; P. du Jardin; J. P. Baudoin

1997-01-01

136

Development of SSR markers and construction of a consensus genetic map for chicory ( Cichorium intybus L.)  

Microsoft Academic Search

A consensus genetic map for chicory (2n = 2x = 18) was obtained after the integration of molecular marker data of two industrial chicory progenies (K28K59, Rubis118)\\u000a and one witloof chicory progeny (BR). As a limited number of co-dominant markers was available at the beginning of this work,\\u000a three different microsatellite-enriched libraries were produced from genomic DNA, resulting in 420, 719 and 1,251 sequences,

T. Cadalen; M. Mörchen; C. Blassiau; A. Clabaut; I. Scheer; J. L. Hilbert; T. Hendriks; M. C. Quillet

2010-01-01

137

Evaluation of genetic relationships among botanical varieties of cultivated peanut (Arachis hypogaea L.) using AFLP markers  

Microsoft Academic Search

Forty-four accessions of cultivated peanut (Arachis hypogaea L.) representing sixbotanical varieties of two subspecies along with three accessions ofthe wild relative A. monticola Krapov et Rigoni were evaluated for their genetic relationships using theAFLP marker technology. Fifteen AFLP primer pairs (EcoRI\\/MseI) generated 28distinct polymorphic markers that were employed to develop uniqueprofiles of all accessions and to construct a phenogram. The

Guohao He; Channapatna Prakash

2001-01-01

138

Genetic mapping of expressed sequence tag polymorphism (ESTP) markers in loblolly pine (Pinus taeda L.)  

Microsoft Academic Search

The development and mapping of genetic markers based upon expressed sequence tag polymorphisms (ESTPs) in loblolly pine (Pinus taeda L.) are reported. The new markers were generated by PCR-amplification of loblolly pine genomic DNAs with primers designed\\u000a from sequenced cDNAs. The cDNA libraries were constructed from RNAs expressed in the needles of loblolly pine seedlings or\\u000a in the xylem from

B. Temesgen; G. R. Brown; D. E. Harry; C. S. Kinlaw; M. M. Sewell; D. B. Neale

2001-01-01

139

Detection of lung cancer using multiple genetic markers--a systematic review.  

PubMed

Lung cancer is the leading cause of cancer deaths worldwide, and has one of the lowest survival rates of any solid tumor. In recent years, several attempts have been conducted to improve an early or accelerated diagnosis due to better overall prognosis after therapy. The aim of this study was evaluating the use of genetic markers for diagnosis of lung cancer. This study was conducted in accordance to Transparent Reporting of Systematic Reviews and Meta-Analyses. Three Internet sources were used to search: MEDLINE-PubMed, EMBASE, and LILACS. The databases were searched for studies conducted in the period up to and including May 10, 2011. The following inclusion criteria were applied: lung cancer studies, and the use of genetic markers for diagnosis. Studies using animal models, review articles, meta-analyses, abstracts, conference proceedings, editorials/letters, case reports, incorrect study population, inadequate data, and cytology was not obtained, were excluded. A total of 1,901 abstracts/citations were identified for preliminary review. From 24 final selected studies, 17 referred to chromosomal markers diagnosis, eight to genes as marker, and one to both subjects. Fluorescence in situ hybridization (FISH) was applied in all studies. Despite the limitations of this study, application of genetic markers to lung cancer diagnosis seems to have prognosis value irrespective of detection methodology used. FISH was the main technique applied to diagnose genetics alterations and revealed a high specificity, although some authors reported low sensitivity. PMID:23513001

Quintans, Jullyana S S; Antoniolli, Angelo R; Onofre, Fabiana M B; Onofre, Alexandre Sherlley C

2013-03-20

140

Diversity Array Technology Markers: Genetic Diversity Analyses and Linkage Map Construction in Rapeseed (Brassica napus L.)  

PubMed Central

We developed Diversity Array Technology (DArT) markers for application in genetic studies of Brassica napus and other Brassica species with A or C genomes. Genomic representation from 107 diverse genotypes of B. napus L. var. oleifera (rapeseed, AACC genomes) and B. rapa (AA genome) was used to develop a DArT array comprising 11 520 clones generated using PstI/BanII and PstI/BstN1 complexity reduction methods. In total, 1547 polymorphic DArT markers of high technical quality were identified and used to assess molecular diversity among 89 accessions of B. napus, B. rapa, B. juncea, and B. carinata collected from different parts of the world. Hierarchical cluster and principal component analyses based on genetic distance matrices identified distinct populations clustering mainly according to their origin/pedigrees. DArT markers were also mapped in a new doubled haploid population comprising 131 lines from a cross between spring rapeseed lines ‘Lynx-037DH’ and ‘Monty-028DH’. Linkage groups were assigned on the basis of previously mapped simple sequence repeat (SSRs), intron polymorphism (IP), and gene-based markers. The map consisted of 437 DArT, 135 SSR, 6 IP, and 6 gene-based markers and spanned 2288 cM. Our results demonstrate that DArT markers are suitable for genetic diversity analysis and linkage map construction in rapeseed.

Raman, Harsh; Raman, Rosy; Nelson, Matthew N.; Aslam, M.N.; Rajasekaran, Ravikesavan; Wratten, Neil; Cowling, Wallace A.; Kilian, A.; Sharpe, Andrew G.; Schondelmaier, Joerg

2012-01-01

141

Serological and biochemical genetic markers and their associations with psychiatric disorders : a review.  

PubMed

The studies pertaining to associations of serological and biochemical genetic markers (blood groups in particular and scrum proteins and enzymes in general) with the psychiatric disorders such as psychoses in general, Schizophrenia, manic-depressive psychosis including unipolar and bipolar affective disorders and neuroses have been critically examined. The reasons for inconsistent findings of various investigators have been pointed out to assist the future researchers to overcome the previous drawbacks. Implications of associations of genetic markers with the psychiatric disorders have been discussed and future areas of research suggested. PMID:21847304

Balgir, R S

1983-10-01

142

A comparison of four methods for detecting weak genetic structure from marker data  

PubMed Central

Genetic structure is ubiquitous in wild populations and is the result of the processes of natural selection, genetic drift, mutation, and gene flow. Genetic drift and divergent selection promotes the generation of genetic structure, while gene flow homogenizes the subpopulations. The ability to detect genetic structure from marker data diminishes rapidly with a decreasing level of differentiation among subpopulations. Weak genetic structure may be unimportant over evolutionary time scales but could have important implications in ecology and conservation biology. In this paper we examine methods for detecting and quantifying weak genetic structures using simulated data. We simulated populations consisting of two putative subpopulations evolving for up to 50 generations with varying degrees of gene flow (migration), and varying amounts of information (allelic diversity). There are a number of techniques available to detect and quantify genetic structure but here we concentrate on four methods: FST, population assignment, relatedness, and sibship assignment. Under the simple mating system simulated here, the four methods produce qualitatively similar results. However, the assignment method performed relatively poorly when genetic structure was weak and we therefore caution against using this method when the analytical aim is to detect fine-scale patterns. Further work should examine situations with different mating systems, for example where a few individuals dominate reproductive output of the population. This study will help workers to design their experiments (e.g., sample sizes of markers and individuals), and to decide which methods are likely to be most appropriate for their particular data.

Jones, Owen R; Wang, Jinliang

2012-01-01

143

ISSR markers as a tool for the assessment of genetic diversity in Passiflora.  

PubMed

Genetic variation among sweet, purple, and yellow passion fruit accessions was assessed using inter-simple sequence repeat (ISSR) markers. Eighteen ISSR primers were used to evaluate 45 accessions. The number of polymorphic bands per primer varied from 4 to 22, with 12.4 bands per primer on average. Nei's genetic distance between accessions ranged from 0.04 to 0.35. Clustering using the neighbor-joining method resulted in the formation of 11 major clusters. It was not possible to classify the accessions according to their geographic origin, showing that there is no structure in the gene bank. The overall mean Shannon-Weaver diversity index was 0.32, indicating good resolution of genetic diversity in passion fruit germplasm using ISSR markers. Our results indicate that ISSR can be useful for genetic diversity studies, to provide practical information for parental selection and to assist breeding and conservation strategies. PMID:21424702

dos Santos, Lucas Ferraz; de Oliveira, Eder Jorge; dos Santos Silva, Aline; de Carvalho, Fabiana Moraes; Costa, Juliana Leles; Pádua, Juliano Gomes

2011-03-22

144

Microsatellite isolation and marker development in carrot - genomic distribution, linkage mapping, genetic diversity analysis and marker transferability across Apiaceae  

PubMed Central

Background The Apiaceae family includes several vegetable and spice crop species among which carrot is the most economically important member, with ~21 million tons produced yearly worldwide. Despite its importance, molecular resources in this species are relatively underdeveloped. The availability of informative, polymorphic, and robust PCR-based markers, such as microsatellites (or SSRs), will facilitate genetics and breeding of carrot and other Apiaceae, including integration of linkage maps, tagging of phenotypic traits and assisting positional gene cloning. Thus, with the purpose of isolating carrot microsatellites, two different strategies were used; a hybridization-based library enrichment for SSRs, and bioinformatic mining of SSRs in BAC-end sequence and EST sequence databases. This work reports on the development of 300 carrot SSR markers and their characterization at various levels. Results Evaluation of microsatellites isolated from both DNA sources in subsets of 7 carrot F2 mapping populations revealed that SSRs from the hybridization-based method were longer, had more repeat units and were more polymorphic than SSRs isolated by sequence search. Overall, 196 SSRs (65.1%) were polymorphic in at least one mapping population, and the percentage of polymophic SSRs across F2 populations ranged from 17.8 to 24.7. Polymorphic markers in one family were evaluated in the entire F2, allowing the genetic mapping of 55 SSRs (38 codominant) onto the carrot reference map. The SSR loci were distributed throughout all 9 carrot linkage groups (LGs), with 2 to 9 SSRs/LG. In addition, SSR evaluations in carrot-related taxa indicated that a significant fraction of the carrot SSRs transfer successfully across Apiaceae, with heterologous amplification success rate decreasing with the target-species evolutionary distance from carrot. SSR diversity evaluated in a collection of 65 D. carota accessions revealed a high level of polymorphism for these selected loci, with an average of 19 alleles/locus and 0.84 expected heterozygosity. Conclusions The addition of 55 SSRs to the carrot map, together with marker characterizations in six other mapping populations, will facilitate future comparative mapping studies and integration of carrot maps. The markers developed herein will be a valuable resource for assisting breeding, genetic, diversity, and genomic studies of carrot and other Apiaceae.

2011-01-01

145

Genetic Markers of Cardiovascular Disease in Rheumatoid Arthritis  

PubMed Central

Cardiovascular (CV) disease is the most common cause of premature mortality in patients with rheumatoid arthritis (RA). It is the result of an accelerated atherosclerotic process. Both RA and atherosclerosis are complex polygenic diseases. Besides traditional CV risk factors and chronic inflammation, a number of studies have confirmed the role of genetic factors in the development of the atherogenesis observed in RA. In this regard, besides a strong association between the HLA-DRB1?04 shared epitope alleles and both endothelial dysfunction, an early step in the atherosclerotic process, and clinically evident CV disease, other polymorphisms belonging to genes implicated in inflammatory and metabolic pathways, located inside and outside the HLA region, such as the 308 variant (G > A, rs1800629) of the TNFA locus, the rs1801131 polymorphism (A > C; position + 1298) of the MTHFR locus, or a deletion of 32 base pairs on the CCR5 gene, seem to be associated with the risk of CV disease in patients with RA. Despite considerable effort to decipher the genetic basis of CV disease in RA, further studies are required to better establish the genetic influence in the increased risk of CV events observed in patients with RA.

Rodriguez-Rodriguez, Luis; Lopez-Mejias, Raquel; Garcia-Bermudez, Mercedes; Gonzalez-Juanatey, Carlos; Gonzalez-Gay, Miguel A.; Martin, Javier

2012-01-01

146

Genetic diversity of 'Ubá' mango tree using ISSR markers.  

PubMed

In this study, the genetic diversity of 'Ubá' mango trees cultivated at the Zona da Mata of Minas Gerais State, Brazil, was assessed, to identify whether there is variability in the plants grown in the region, justifying the mass selection as a breeding method. We used 102 accessions. Leaves were collected for extraction of genomic DNA, which was amplified with nine ISSR primers. The data obtained by the analysis of electrophoretic patterns were arranged in a binary matrix, considering 0 for the absence and 1 for the presence of bands. Based on these data, we performed the analysis of genetic dissimilarity and carried out the cluster analysis by the methods of Tocher and graphical dispersion. The most similar accessions are 144 and 150, both coming from Ubá, while the most divergent ones are 29 and 97, from Visconde do Rio Branco. The grouping by the Tocher method separated the accessions into six groups, 94.1% of which were allocated in the first group and showed that there is no separation of accessions depending on the sampling sites. The 3D scatter plot reinforces this conclusion. There is genetic variability among the accessions of 'Ubá' mango tree evaluated. Therefore, it is possible to make mass selection in open-pollinated populations. PMID:21644009

Rocha, Aline; Salomão, Luiz Carlos Chamhum; Salomão, Tânia Maria Fernandes; Cruz, Cosme Damião; de Siqueira, Dalmo Lopes

2012-02-01

147

Genetic markers of cardiovascular disease in rheumatoid arthritis.  

PubMed

Cardiovascular (CV) disease is the most common cause of premature mortality in patients with rheumatoid arthritis (RA). It is the result of an accelerated atherosclerotic process. Both RA and atherosclerosis are complex polygenic diseases. Besides traditional CV risk factors and chronic inflammation, a number of studies have confirmed the role of genetic factors in the development of the atherogenesis observed in RA. In this regard, besides a strong association between the HLA-DRB1?04 shared epitope alleles and both endothelial dysfunction, an early step in the atherosclerotic process, and clinically evident CV disease, other polymorphisms belonging to genes implicated in inflammatory and metabolic pathways, located inside and outside the HLA region, such as the 308 variant (G > A, rs1800629) of the TNFA locus, the rs1801131 polymorphism (A > C; position + 1298) of the MTHFR locus, or a deletion of 32 base pairs on the CCR5 gene, seem to be associated with the risk of CV disease in patients with RA. Despite considerable effort to decipher the genetic basis of CV disease in RA, further studies are required to better establish the genetic influence in the increased risk of CV events observed in patients with RA. PMID:22927710

Rodríguez-Rodríguez, Luis; López-Mejías, Raquel; García-Bermúdez, Mercedes; González-Juanatey, Carlos; González-Gay, Miguel A; Martín, Javier

2012-08-02

148

Genetic Relationship of Curcuma Species from Northeast India Using PCR-Based Markers  

Microsoft Academic Search

Molecular genetic fingerprints of nine Curcuma species from Northeast India were developed using PCR-based markers. The aim involves elucidating there intra- and inter-specific\\u000a genetic diversity important for utilization, management, and conservation. Twelve random amplified polymorphic DNA (RAPD),\\u000a 19 Inter simple sequence repeats (ISSRs), and four amplified fragment length polymorphism (AFLP) primers produced 266 polymorphic\\u000a fragments. ISSR confirmed maximum polymorphism of

Archana Das; Vigya Kesari; Vinod M. Satyanarayana; Ajay Parida; Latha Rangan

2011-01-01

149

Autism and genetics: Clinical approach and association study with two markers of HRAS gene  

Microsoft Academic Search

Twin studies and familial aggregation studies indicate that genetic factors could play a role in infantile autism. In an earlier study, we identified a possible positive association between autism and a c-Harvey-ras (HRAS) oncogene marker at the 3â² end of the coding region. In an attempt to confirm this finding, we studied a larger population, well-characterized clinically and genetically. We

J. Herault; Elisabeth Petit; C. Cherpi; Anne Perrot; Pascal Lenoir; Catherine Barthélémy; Dominique Sauvage; Jacques Mallet; Jean Pierre Müh; Gilbert Lelord

1995-01-01

150

Development of Molecular Markers for Detecting Genetic Relationships Within and Among Six Egyptian Buffalo Locations  

Microsoft Academic Search

Genetic variations was detected in Egyptian buffaloes at six locations; El-Behira (Be), El-Sharkia (Sh), El-Menofia (Me), Kafr El-Sheikh (Kf), El-Menia (Mn) and Sohag (So). Ten individuals from each location were blood sampled. SDS-protein and esterase markers were used to detect the genetic variations within the six studied location. SDS-protein profiles showed lower percentage of polymorphism (21.5%) than esterase profiles (45.7%)

A. H. Atta; E. S. Ahmed; M. H. Sadek; A. A. Amin

2009-01-01

151

Genetic diversity of wild coffee ( Coffea arabica L.) using molecular markers  

Microsoft Academic Search

Genetic diversity was studied using RAPD markers among119 coffee (Coffea arabica L.) individuals representing 88 accessions derived from spontaneous and subspontaneous trees in Ethiopia, the primary centre\\u000a of species diversity, six cultivars grown locally in Ethiopia, and two accessions derived from the genetic populations Typica\\u000a and Bourbon, spread in the 18th century, which gave rise to the most currently grown

F. Anthony; B. Bertrand; O. Quiros; A. Wilches; P. Lashermes; J. Berthaud; A. Charrier

2001-01-01

152

Enhancement of Absolute Fracture Risk Prognosis with Genetic Marker: The Collagen I Alpha 1 Gene  

Microsoft Academic Search

An important objective of genetic research in osteoporosis is to translate genotype data into the prognosis of fracture. The\\u000a present study sought to develop a prognostic model for predicting osteoporotic fracture by using information from a genetic\\u000a marker and clinical risk factors. It was designed as a prospective epidemiological study which involved 894 women of Caucasian\\u000a background aged 60+ years

Bich N. H. Tran; Nguyen D. Nguyen; John A. Eisman; Tuan V. Nguyen

2009-01-01

153

Genetic diversity of Iranian soft-seed pomegranate genotypes as revealed by fluorescent-AFLP markers  

Microsoft Academic Search

The amplified fragment length polymorphism (AFLP) technique was used to examine the genetic relationships among 21 Iranian\\u000a soft-seeded pomegranate (Punica granatum L.) genotypes. Out of 72 fluorescent-AFLP primer combinations screened, 31 were selected to produce the 503 polymorphic markers\\u000a used in this study. Genetic similarity estimates between genotypes, calculated by the Jaccard’s similarity coefficient, ranged\\u000a from 0.17 to 1.00, while

Ali Sarkhosh; Zabihollah Zamani; Reza Fatahi; Mohammad E. Hassani; Claudia Wiedow; Emily Buck; Susan E. Gardiner

2011-01-01

154

Latino Populations: A Unique Opportunity for the Study of Race, Genetics, and Social Environment in Epidemiological Research  

PubMed Central

Latinos are the largest minority population in the United States. Although usually classified as a single ethnic group by researchers, Latinos are heterogeneous from cultural, socioeconomic, and genetic perspectives. From a cultural and social perspective, Latinos represent a wide variety of national origins and ethnic and cultural groups, with a full spectrum of social class. From a genetic perspective, Latinos are descended from indigenous American, European, and African populations. We review the historical events that led to the formation of contemporary Latino populations and use results from recent genetic and clinical studies to illustrate the unique opportunity Latino groups offer for studying the interaction between racial, genetic, and environmental contributions to disease occurrence and drug response.

Gonzalez Burchard, Esteban; Borrell, Luisa N.; Choudhry, Shweta; Naqvi, Mariam; Tsai, Hui-Ju; Rodriguez-Santana, Jose R.; Chapela, Rocio; Rogers, Scott D.; Mei, Rui; Rodriguez-Cintron, William; Arena, Jose F.; Kittles, Rick; Perez-Stable, Eliseo J.; Ziv, Elad; Risch, Neil

2005-01-01

155

Expanding possibilities for intervention against small ruminant lentiviruses through genetic marker-assisted selective breeding.  

PubMed

Small ruminant lentiviruses include members that infect sheep (ovine lentivirus [OvLV]; also known as ovine progressive pneumonia virus/maedi-visna virus) and goats (caprine arthritis encephalitis virus [CAEV]). Breed differences in seroprevalence and proviral concentration of OvLV had suggested a strong genetic component in susceptibility to infection by OvLV in sheep. A genetic marker test for susceptibility to OvLV has been developed recently based on the TMEM154 gene with validation data from over 2,800 sheep representing nine cohorts. While no single genotype has been shown to have complete resistance to OvLV, consistent association in thousands of sheep from multiple breeds and management conditions highlight a new strategy for intervention by selective breeding. This genetic marker-assisted selection (MAS) has the potential to be a useful addition to existing viral control measures. Further, the discovery of multiple additional genomic regions associated with susceptibility to or control of OvLV suggests that additional genetic marker tests may be developed to extend the reach of MAS in the future. This review will cover the strengths and limitations of existing data from host genetics as an intervention and outline additional questions for future genetic research in sheep, goats, small ruminant lentiviruses, and their host-pathogen interactions. PMID:23771240

White, Stephen N; Knowles, Donald P

2013-06-14

156

Epidemiological Association of Different Campylobacter jejuni Groups with Metabolism-Associated Genetic Markers ? †  

PubMed Central

In this study, multilocus sequence typing (MLST) was combined with the genetic detection of six genetic markers, ansB, dmsA, ggt, cj1585c, cjj81176-1367/71 (cj1365c), and the two-gene marker tlp7 (cj0951c plus cj0952c), to assess if their presence correlated with different C. jejuni clonal groups. Using a collection of 266 C. jejuni isolates from (in decreasing order of sample size) humans, chickens, cattle, and turkeys, it was further investigated whether the resulting genotypes correlated with the isolation source. We found combinations of the six marker genes to be mutually exclusive, and their patterns of presence or absence correlated to some degree with animal source. Together with MLST results, the obtained genotypes could be segregated into six groups. An association was identified for ansB, dmsA, and ggt with the MLST-clonal complexes (MLST-CC) 22, 42, 45, and 283, which formed the most prominent group, in which chickens were the most prevalent animal source. Two other groups, characterized by the presence of cj1585c, cjj81176-1367/71, and the two-gene marker tlp7, associated with either MLST-CC 21 or 61, were overrepresented in isolates of bovine origin. Mutually exclusive marker gene combinations were observed for ansB, dmsA, and ggt, typically found in CC 45 and the related CC 22, 42, and 283, whereas the other three marker genes were found mostly in CC 21, 48, and 206. The presence of the two-gene marker tlp7, which is typical for MLST 21 and 53 as well as for MLST-CC 61, strongly correlates with a bovine host; this is interpreted as an example of host adaptation. In cases of C. jejuni outbreaks, these genetic markers could be helpful for more effective source tracking.

Zautner, Andreas E.; Herrmann, Sahra; Corso, Jasmin; Tareen, A. Malik; Alter, Thomas; Gross, Uwe

2011-01-01

157

Multiplexed microsatellite markers for genetic studies of beech.  

PubMed

European beech (Fagus sylvatica L.) is one of the economically most important broadleaved tree species in Europe and has become a model for studying climate change effects on forests. Multiplex PCR of microsatellites is a fast and cost-effective technique allowing high-throughput genotyping. Here we present the procedure used to develop two multiplex kits (8-plexes) for European beech. We paid particular attention to quality control throughout all steps of the multiplex kits development (null allele detection, error rate measurements, linkage disequilibrium). Preliminary assays suggest that the 16 amplified loci are largely devoid of null alleles and allow rapid and cost-effective genotyping of beech with low error rates. The two kits, which differ in their levels of polymorphism, most likely due to marker origin, were also informative in seven other beech species tested. PMID:22145937

Lefèvre, S; Wagner, S; Petit, R J; de Lafontaine, G

2011-12-07

158

[Genetic variation analysis of wild populations of grass carp (Ctenopharyngodon idella) using microsatellite markers].  

PubMed

Twelve microsatellites were used to analyze the genetic diversity and genetic structure of eight wild populations of grass carp, among which six populations from Yangtze River (Hanjiang, Wujian, Jiujiang, Shishou, Mudong, and Wanzhou), one population from Pearl River and Heilongjiang River for each, Zhaoqing, and Nenjiang, respectively. Twelve markers showed highly polymorphic and all the eight populations contained high genetic variations. The variations of six populations of Yangtze River and Zhaoqing population of Pearl River were higher than Nenjiang population of Heilongjiang River. Bottleneck analysis revealed that four populations (Zhaoqing, Nenjiang, Mudong, and Wangzhou) had experienced a recent genetic bottleneck, and the effective population size was reduced. Pairwise FST and AMOVA analysis detected significant genetic difference among populations. The pairwise population genetic distances and the UPGMA tree demonstrated that the genetic distances between six populations of Yangtze River and Zhaoqing population were closer and clustered together earlier, as compared to those populations with Nenjiang population. The genetic structure simulation analysis suggested that there were five logic populations of all individuals. The genetic structures of Zhaoqing and Nenjiang populations were shown with independent separation, but the genetic structures of populations from Yangtze River were shown with fuzzy distribution. The high diversity was found in the wild grass carp from three major watersheds in China, which would supply a basis for future genetic improvement. However, the bottleneck effect of some populations should be taken into account in the practical breeding programs. PMID:23448932

Fu, Jian-Jun; Li, Jia-Le; Shen, Yu-Bang; Wang, Rong-Quan; Xuan, Yun-Feng; Xu, Xiao-Yan; Chen, Yong

2013-02-01

159

Genetic diversity analysis of Bt cotton genotypes in Pakistan using simple sequence repeat markers.  

PubMed

The popularity of genetically modified insect resistant (Bt) cotton has promoted large scale monocultures, which is thought to worsen the problem of crop genetic homogeneity. Information on genetic diversity among Bt cotton varieties is lacking. We evaluated genetic divergence among 19 Bt cotton genotypes using simple sequence repeat (SSR) markers. Thirty-seven of 104 surveyed primers were found informative. Fifty-two primers selected on the basis of reported intra-hirsutum polymorphism in a cotton marker database showed a high degree of polymorphism, 56% compared to 13% for randomly selected primers. A total of 177 loci were amplified, with an average of 1.57 loci per primer, generating 38 markers. The amplicons ranged in size from 98 to 256 bp. The genetic similarities among the 19 genotypes ranged from 0.902 to 0.982, with an average of 0.947, revealing a lack of diversity. Similarities among genotypes from public sector organizations were higher than genotypes developed by private companies. Hybrids were found to be more distant compared to commercial cultivars and advanced breeding lines. Cluster analysis grouped the 19 Bt cotton genotypes into three major clusters and two independent entries. Cultivars IR-3701, Ali Akbar-802 and advanced breeding line VH-259 grouped in subcluster B2, with very narrow genetic distances despite dissimilar parentage. We found a very high level of similarity among Pakistani-bred Bt cotton varieties, which means that genetically diverse recurrent parents should be included to enhance genetic diversity. The intra-hirsutum polymorphic SSRs were found to be highly informative for molecular genetic diversity studies in these cotton varieties. PMID:22535395

Ullah, I; Iram, A; Iqbal, M Z; Nawaz, M; Hasni, S M; Jamil, S

2012-03-14

160

Pollen genetic markers for detection of mutagens in the environment.  

PubMed Central

To utilize and exploit pollen for in situ mutagen monitoring, screening and toxicology, the range of genetic traits in pollen must be identified and analyzed. Traits that can be considered include ornamentation, shape and form, male sterility viability, intraspecific incompatibility, proteins and starch deposition. To be useful for the development of mutagen detection systems proteins should be: (1) activity stainable or immunologically identifiable in the pollen, (2) the products of one to three loci, and (3) gametophytic and nuclear in origin. Several proteins including alcohol dehydrogenase in maize, which meet those criteria will be discussed. The waxy locus in barley and maize which controls starch deposition has been characterized genetically and methods have been developed for pollen screening and mutant detection. At Washington State University a waxy pollen system is being developed in barley for in situ mutagen monitoring. The basis is an improved method for staining and scoring waxy pollen mutants. Specific base substitution, frameshift, and deletion mutant lines are being developed to provide information about the nature of the mutations induced by environmental mutagens. Thirty waxy mutant lines, induced by sodium azide and gamma-rays have been selected and are being characterized for spontaneous and induced reversion frequencies, allelism, karyotype, amylose content, and UDP glucose glucosyltransferase (waxy gene product) activity. Twelve mutant alleles are being mapped by recombinant frequencies.

Nilan, R A; Rosichan, J L; Arenaz, P; Hodgdon, A L; Kleinhofs, A

1981-01-01

161

Quantum dots and microfluidic single-molecule detection for screening genetic and epigenetic cancer markers in clinical samples  

NASA Astrophysics Data System (ADS)

Genomic analysis of biomarkers, including genetic markers such as point mutations and epigenetic markers such as DNA methylation, has become a central theme in modern disease diagnosis and prognosis. Recently there is an increasing interest in using single-molecule detection (SMD) for genomic detection. The driving force not only comes from its ultrahigh sensitivity that can allow the detection of low-abundance nucleic acids with reduced or without the need of amplification but also from its potential in achieving high-accuracy quantification of rare targets via singlemolecule sorting. The unique photophysical properties of semiconductor quantum dots (QDs) have made them ideal for use as spectral labels and luminescent probes. QDs also make excellent donors to pair with organic dyes in the fluorescence resonance energy transfer (FRET) process due to the features of narrow emission spectra and small Stokes shift. We have developed highly sensitive, quantitative and clinically relevant technologies for analysis of genomic markers based on the convergence of SMD, microfluidic manipulations, and quantum dot fluorescence resonance energy transfer technology (QD-FRET). Extraordinary performances of these new technologies have been exemplified by analysis of a variety of biomarkers including point mutations, DNA integrity and DNA methylation in clinical samples.

Wang, Tza-Huei; Bailey, Vasudev; Liu, Kelvin

2011-05-01

162

Spectroscopic detection of fluorescent protein marker gene activity in genetically modified plants  

Microsoft Academic Search

This work focuses on developing a portable fibre optic fluorescence analyser for rapid identification of genetically modified plants tagged with a fluorescent marker gene. Independent transgenic tobacco plant lines expressing the enhanced green fluorescence protein (EGFP) gene were regenerated following Agrobacterium-mediated gene transfer. Molecular characterisation of these plant lines was carried out at the DNA level by PCR screening to

O. W. Liew; Jenny P. C. Chong; Anand K. Asundi

2005-01-01

163

Quantitative PCR for Detection and Enumeration of Genetic Markers of Bovine Fecal Pollution  

EPA Science Inventory

Accurate assessment of health risks associated with bovine (cattle) fecal pollution requires a reliable host-specific genetic marker and a rapid quantification method. We report the development of quantitative PCR assays for the detection of two recently described cow feces-spec...

164

Analysis of genetic diversity in Ganoderma population with a novel molecular marker SRAP  

Microsoft Academic Search

Genetic marker technology designed to detect naturally occurring polymorphisms at the DNA level had become an invaluable and revolutionizing tool for both applied and basic studies of fungi. To eliminate the confusion on the taxonomy of Ganoderma strains, in this study, a collection of 31 accessions representative of morphotypes and some unclassified types was used for analyzing molecular diversity using

Shu-Jing Sun; Wei Gao; Shu-Qian Lin; Jian Zhu; Bao-Gui Xie; Zhi-Bin Lin

2006-01-01

165

Molecular genetic diversity of Punica granatum L. (pomegranate) as revealed by microsatellite DNA markers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pomegranate (Punica granatum L.) is one of the oldest known edible fruits and more and more it arouse interest of scientific community given its numerous biological activities. However, information about its genetic resources and characterization using reliable molecular markers are still scarce. In...

166

ASSESSMENT OF GENETIC DIVERSITY IN BULB ONION (ALLIUM CEPA L.) USING SIMPLE SEQUENCE REPEAT MARKERS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Onions are the second most-valuable vegetable in the world, following only tomato. Despite their economic significance, knowledge of onion genetic diversity and resources is limited, owing to a paucity of public marker and germplasm resources and their out-breeding, biennial habit. The unusually l...

167

Genetic management of broodstock populations with DNA markers in rainbow trout  

Technology Transfer Automated Retrieval System (TEKTRAN)

DNA markers are very useful for aquaculture and fisheries broodstock management. They have been used for parentage assignment when spawning families share common environments, and to evaluate genetic parameters in broodstock populations. The selective breeding program at the National Center for Cool...

168

Preliminary Genetic Map of Hydrangea macrophylla Using SSR Markers and a Pseudo-Testcross Strategy  

Technology Transfer Automated Retrieval System (TEKTRAN)

We used a “two-way pseudo-testcross” mapping strategy in combination with simple sequence repeat (SSR) markers to construct a genetic map of Hydrangea macrophylla. Mapping populations were developed from reciprocal crosses between two divergent cultivars, “Bailmer” and “Veitchii”. “Bailmer”, which i...

169

Fingerprinting fission yeast: polymorphic markers for molecular genetic analysis of Schizosaccharomyces pombe strains  

Microsoft Academic Search

The fission yeast Schizosaccharomyces pombe is widely used as a model eukaryote for cell and molecular studies but little is known of natural genetic variation in this species. In order to obtain informative molecular markers, imperfect tandem repeats, identified through bioinformatic methods, were tested for length polymorphism in six wild-type strains of Sch. pombe isolated from different substrates and geographical

Ann-Marie Patch; Stephen J. Aves

2007-01-01

170

HIGH-RESOLUTION GENETIC MAP OF BOVINE CHROMOSOME 29 THROUGH FOCUSED MARKER DEVELOPMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Chromosome-specific libraries aid in the development of genetic maps and focus marker development in areas of the genome with identified QTL. A small-insert BTA29 library constructed by microdissection of a 1:29 Rb-fusion cell line, was screened for dinucleotide repeats (CA) 15 and/or (GA) 15. App...

171

Genetic Structure of Wild Rice Oryza Glumaepatula Populations in Three Brazilian Biomes Using Microsatellite Markers  

Microsoft Academic Search

The existence of Oryza glumaepatula is threatened by devastation and, thus, the implementation of conservation strategies is extremely relevant. This study aimed to characterize the genetic variability and estimate population parameters of 30 O. glumaepatula populations from three Brazilian biomes using 10 microsatellite markers. The levels of allelic variability for the SSR loci presented a mean of 10.3 alleles per

Rosana Pereira Vianello Brondani; Maria Imaculada Zucchi; Claudio Brondani; Paulo Hideo Nakano Rangel; Tereza Cristina De Oliveira Borba; Priscila Nascimento Rangel; Mara Rubia Magalhães; Roland Vencovsky

2005-01-01

172

Application of marker selection to enhance estimation of genetic effects and gene interaction in cattle  

Technology Transfer Automated Retrieval System (TEKTRAN)

Selection on important genetic markers can improve estimates of additive and dominance association effects. A composite population of beef cattle was selected for intermediate frequencies of myostatin (GDF8) F94L and µ-calpain (CAPN1) polymorphisms. Important additive associations of the GDF8 locu...

173

Cotransduction and Cotransformation of Genetic Markers in Bacillus Subtilis and Bacillus Licheniformis.  

National Technical Information Service (NTIS)

Bacteriophage SP-15, a large generalized transducing phage of Bacillus, was compared with phages PBS-1 and SP-10 for the ability to cotransduce pairs of genetic markers exhibiting different degrees of linkage. When auxotrophs of B. subtilis W-23 were used...

F. J. Tyeryar M. J. Taylor W. D. Lawton I. D. Goldberg

1969-01-01

174

Detection of genetic diversity and selective gene introgression in coffee using RAPD markers  

Microsoft Academic Search

RAPD (randomly amplified polymorphic DNA) markers generated by arbitary decamers have been successfully employed to detect genetic polymorphisms between coffee species and between Coffea arabica genotypes. The RAPD profiles were used to construct dendrograms and these were consistent with the known history and evolution of Coffea arabica. Material originating from Ethiopia and the arabica sub-groups — C. arabica var. typica

C. Orozco-Castillo; K. J. Chalmers; R. Waugh; W. Powell

1994-01-01

175

Study of genetic diversity in Chamomile ( Matricaria chamomilla) based on morphological traits and molecular markers  

Microsoft Academic Search

Chamomile is one of the most important medicinal plants in the world trade that has many applications in drug and sanitary industrials. In order to evaluate the genetic diversity of different chamomile landraces based on morphological and molecular markers, 20 landraces were collected from different area of Iran. In addition to that, five populations imported from European were examined. The

M. Solouki; H. Mehdikhani; H. Zeinali; A. A. Emamjomeh

2008-01-01

176

Development of microsatellite markers in Cannabis sativa for DNA typing and genetic relatedness analyses  

Microsoft Academic Search

Microsatellite markers were developed for Cannabis sativa L. (marijuana) to be used for DNA typing (genotype identification) and to measure the genetic relationships between the different plants. Twelve different oligonucleotide probes were used to screen an enriched microsatellite library of Cannabis sativa in which 49% of the clones contained microsatellite sequences. Characterization of microsatellite loci in Cannabis revealed that GA\\/CT

H. J. Alghanim; J. R. Almirall

2003-01-01

177

Genetic diversity in section Rhizomatosae of the genus Arachis (Fabaceae) based on microsatellite markers  

Microsoft Academic Search

The genus Arachis (Fabaceae) native to South America, contains 80 species divided into nine sections, three of which contain species of special economic importance such as the cultivated peanut (Arachis hypogaea), belonging to the section Arachis, and some perennial forage species from sections Caulorrhizae and Rhizomatosae. We used microsatellite markers to assay genetic variability among 77 accessions of four species

Andrea Akemi Hoshino; Paula Macedo Nóbile; Dario Abel Palmieri; José F. Montenegro Valls; Marcos A. Gimenes; Catalina Romero Lopes

2008-01-01

178

Random amplified polymorphic DNA (RAPD) markers for genetic analysis in micropropagated plants of Populus deltoides Marsh  

Microsoft Academic Search

RAPD markers were used to assess genetic fidelity of 23 micropropagated plants of a single clone (L34) of Populus deltoides. Eleven arbitrary 10-base primers were successfully used to amplify DNA from in vivo and in vitro material. Of these, 5 distinguished a total of 13 polymorphisms common across 6 micropropagated plants. Apart from these 6 plants, the amplification products were

Vijay Rani; Ajay Parida; S. N. Raina

1995-01-01

179

Molecular genetic diversity of Punica granatum L. (pomegranate) as revealed by microsatellite DNA markers (SSR).  

PubMed

Pomegranate (Punica granatum L.) is one of the oldest known edible fruits and more and more it arouse interest of scientific community given its numerous biological activities. However, information about its genetic resources and characterization using reliable molecular markers are still scarce. In the present study, we report the development of 4 new polymorphic SSR markers. They have been used in addition to 11 SSRs previously published to investigate molecular diversity of 33 P. granatum ecotypes. Based on the multi-locus profiles, twenty-two distinctive genotypes were identified. Globally, quite low genetic diversity has been revealed, as measured by allele richness (2.83 per locus) and heterozygosity (He=0.245; Ho=0.243), reflecting the narrow genetic background of the plant material. Four synonymous groups could be detected involving 15 accessions. Results of ordination and cluster analysis suggested that almost all the Tunisian cultivars share similar genetic background, and are likely derived from a small number of introductions in ancient times. Results issued from this study provide essential information to project a pomegranate core-collection without plant material duplication and for sustainable management of pomegranate landraces at national and international level. Furthermore, these SSR markers are powerful tool for marker assisted selection (MAS) program and for QTL studies. PMID:22123180

Hasnaoui, Nejib; Buonamici, Anna; Sebastiani, Federico; Mars, Messaoud; Zhang, Dapeng; Vendramin, Giovanni G

2011-11-20

180

ISOLATION, CHARACTERIZATION AND DEVELOPMENT OF WRKY GENES AS USEFUL GENETIC MARKERS IN THEOBROMA CACAO  

Technology Transfer Automated Retrieval System (TEKTRAN)

Currently, there is an international effort in improving disease resistance and crop yield in Theobroma cacao L., an economically important crop of the tropics. Molecular genetic markers are powerful tools in selective breeding of crops. The "candidate gene" approach identifies genes that may be i...

181

Miniature inverted-repeat transposable element identification and genetic marker development in Agrostis  

Technology Transfer Automated Retrieval System (TEKTRAN)

Creeping bentgrass (Agrostis stolonifera L.) is an important species to the turfgrass industry because of its adaptation for use in high quality turf stands such as golf course putting greens, tees, and fairways. A. stolonifera is a highly outcrossing allotetraploid making genetic marker developmen...

182

Genetic linkage mapping in peach using morphological, RFLP and RAPD markers  

Microsoft Academic Search

We have constructed a genetic linkage map of peach [Prunus persica (L.) Batsch] consisting of RFLP, RAPD and morphological markers, based on 71 F2 individuals derived from the self-fertilization of four F1 individuals of a cross between ‘New Jersey Pillar’ and KV 77119. This progeny, designated as the West Virginia (WV) family, segregates for genes controlling canopy shape, fruit flesh

S. Rajapakse; L. E. Belthoff; G. He; A. E. Estager; R. Scorza; I. Verde; R. E. Ballard; W. V. Baird; A. Callahan; R. Monet; A. G. Abbott

1995-01-01

183

Spatial Attentional Bias as a Marker of Genetic Risk, Symptom Severity, and Stimulant Response in ADHD  

Microsoft Academic Search

Attention-deficit hyperactivity disorder (ADHD) is a heritable childhood onset disorder that is marked by variability at multiple levels including clinical presentation, cognitive profile, and response to stimulant medications. It has been suggested that this variability may reflect etiological differences, particularly, at the level of underlying genetics. This study examined whether an attentional phenotype-spatial attentional bias could serve as a marker

Mark A Bellgrove; Edwina Barry; Katherine A Johnson; Marie Cox; Aoife Dáibhis; Michael Daly; Ziarih Hawi; David Lambert; Michael Fitzgerald; Fiona McNicholas; Ian H Robertson; Michael Gill; Aiveen Kirley

2008-01-01

184

Estimates of Genetic Differentiation Measured by FST Do Not Necessarily Require Large Sample Sizes When Using Many SNP Markers  

PubMed Central

Population genetic studies provide insights into the evolutionary processes that influence the distribution of sequence variants within and among wild populations. FST is among the most widely used measures for genetic differentiation and plays a central role in ecological and evolutionary genetic studies. It is commonly thought that large sample sizes are required in order to precisely infer FST and that small sample sizes lead to overestimation of genetic differentiation. Until recently, studies in ecological model organisms incorporated a limited number of genetic markers, but since the emergence of next generation sequencing, the panel size of genetic markers available even in non-reference organisms has rapidly increased. In this study we examine whether a large number of genetic markers can substitute for small sample sizes when estimating FST. We tested the behavior of three different estimators that infer FST and that are commonly used in population genetic studies. By simulating populations, we assessed the effects of sample size and the number of markers on the various estimates of genetic differentiation. Furthermore, we tested the effect of ascertainment bias on these estimates. We show that the population sample size can be significantly reduced (as small as n?=?4–6) when using an appropriate estimator and a large number of bi-allelic genetic markers (k>1,000). Therefore, conservation genetic studies can now obtain almost the same statistical power as studies performed on model organisms using markers developed with next-generation sequencing.

Willing, Eva-Maria; Dreyer, Christine; van Oosterhout, Cock

2012-01-01

185

Genetic characteristics of polymorphic antigenic markers among Korean isolates of Plasmodium vivax.  

PubMed

Plasmodium vivax, a protozoan malaria parasite of humans, represents a major public health concern in the Republic of Korea (= South Korea). However, little is known about the genetic properties and population structures of the P. vivax isolates circulating in South Korea. This article reviews known polymorphic genetic markers in South Korean isolates of P. vivax and briefly summarizes the current issues surrounding the gene and population structures of this parasite. The critical genetic characteristics of major antigens of the parasite, such as circumsporozoite protein (CSP), merozoite surface protein 1 (MSP-1) and MSP-3, Duffy binding protein (DBP), apical membrane antigen 1 (AMA-1), and GAM-1, are also discussed. PMID:19885335

Hwang, Seung-Young; Kim, So-Hee; Kho, Weon-Gyu

2009-10-01

186

Genetic marker anchoring by six-dimensional pools for development of a soybean physical map  

PubMed Central

Background Integrated genetic and physical maps are extremely valuable for genomic studies and as important references for assembling whole genome shotgun sequences. Screening of a BAC library using molecular markers is an indispensable procedure for integration of both physical and genetic maps of a genome. Molecular markers provide anchor points for integration of genetic and physical maps and also validate BAC contigs assembled based solely on BAC fingerprints. We employed a six-dimensional BAC pooling strategy and an in silico approach to anchor molecular markers onto the soybean physical map. Results A total of 1,470 markers (580 SSRs and 890 STSs) were anchored by PCR on a subset of a Williams 82 BstY I BAC library pooled into 208 pools in six dimensions. This resulted in 7,463 clones (~1× genome equivalent) associated with 1470 markers, of which the majority of clones (6,157, 82.5%) were anchored by one marker and 1106 (17.5%) individual clones contained two or more markers. This contributed to 1184 contigs having anchor points through this 6-D pool screening effort. In parallel, the 21,700 soybean Unigene set from NCBI was used to perform in silico mapping on 80,700 Williams 82 BAC end sequences (BES). This in silico analysis yielded 9,835 positive results anchored by 4152 unigenes that contributed to 1305 contigs and 1624 singletons. Among the 1305 contigs, 305 have not been previously anchored by PCR. Therefore, 1489 (78.8%) of 1893 contigs are anchored with molecular markers. These results are being integrated with BAC fingerprints to assemble the BAC contigs. Ultimately, these efforts will lead to an integrated physical and genetic map resource. Conclusion We demonstrated that the six-dimensional soybean BAC pools can be efficiently used to anchor markers to soybean BACs despite the complexity of the soybean genome. In addition to anchoring markers, the 6-D pooling method was also effective for targeting BAC clones for investigating gene families and duplicated regions in the genome, as well as for extending physical map contigs.

Wu, Xiaolei; Zhong, Guohua; Findley, Seth D; Cregan, Perry; Stacey, Gary; Nguyen, Henry T

2008-01-01

187

Assessing Genetic Structure with Multiple Classes of Molecular Markers: A Case Study Involving the Introduced Fire Ant Solenopsis invicta  

Microsoft Academic Search

We used 30 genetic markers of 6 different classes to describe hierarchical genetic structure in introduced populations of the fire ant Solenopsis invicta. These included four classes of presumably neutral nuclear loci (allozymes, co- dominant random amplified polymorphic DNAs (RAPDs), microsatellites, and dominant RAPDs), a class comprising two linked protein-coding nuclear loci under selection, and a marker of the mitochondrial

Kenneth G. Ross; D. DeWayne Shoemaker; Michael J. B. Krieger; Christopher J. DeHeer; Laurent Keller

188

Pollen genetic markers for detection of mutagens in the environment  

SciTech Connect

To utilize and exploit pollen for in situ mutagen monitoring, screening and toxicology, the range of genetic traits in pollen must be identified and analyzed. To be useful for the development of mutagen detection systems proteins should be: (1) activity stainable or immunologically identifiable in the pollen, (2) the products of one to three loci; and (3) gametophytic and nuclear in origin. Several proteins, including alcohol dehydrogenase in maize, which meet these criteria are discussed. The waxy locus in barley and maize which controls starch deposition for pollen screening and mutant detection. Thirty waxy mutant lines, induced by sodium azide and gamma-rays are characterized for spontaneous and induced reversion frequencies, allelism, karyotype, amylose content, and UDPglucose glucosyltransferase (waxy gene product) activity. Twelve mutant alleles are being mapped by recombinant frequencies.

Nilan, R.A.; Rosichan, J.L.; Arenaz, P.; Hodgdon, A.L.; Kleinhofs, A.

1980-01-01

189

Population genetic data for 17 STR markers from Lebanon.  

PubMed

Seventeen autosomal STRs were analyzed (D2S1338, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D19S433, D21S11, CSF1PO, FGA, TH01, TPOX, vWA, Penta D, and Penta E) in the Lebanese population. A total of 192 unrelated individuals were genotyped for the 15 autosomal STRs in the Promega PowerPlex 16 STR kit. An additional 275 unrelated individuals were genotyped for the Applied Biosystems AmpFlSTR Identifiler and SGM+STR kits. Allele frequencies for the shared CODIS 13 loci among the three STR kits tested were not significantly different among individuals within the Lebanese population. Forensic and population genetic parameters for the 17 loci were calculated. We also compared the allele frequencies from this population with other populations in the same geographic vicinity. PMID:20863737

Chouery, Eliane; Coble, Michael D; Strouss, Katharine M; Saunier, Jessica L; Jalkh, Nadine; Medlej-Hashim, Myrna; Ayoub, Fouad; Mégarbané, André

2010-09-21

190

Evidence for intragenic recombination within a novel genetic marker that distinguishes mussels in the Mytilus edulis species complex  

Microsoft Academic Search

We have used the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques to design two genetic markers for blue mussels in the Mytilus edulis species complex. Both of these markers target the gene encoding the mussel polyphenolic adhesive protein. The first marker, Glu-5?, is highly differentiated among and can be used to identify the three blue mussel

Paul D Rawson; Karen L Joyner; Keith Meetze; Thomas J Hilbish

1996-01-01

191

Marker-Based Quantitative Genetics in the Wild?: The Heritability and Genetic Correlation of Chemical Defenses in Eucalyptus  

PubMed Central

Marker-based methods for estimating heritability and genetic correlation in the wild have attracted interest because traditional methods may be impractical or introduce bias via G × E effects, mating system variation, and sampling effects. However, they have not been widely used, especially in plants. A regression-based approach, which uses a continuous measure of genetic relatedness, promises to be particularly appropriate for use in plants with mixed-mating systems and overlapping generations. Using this method, we found significant narrow-sense heritability of foliar defense chemicals in a natural population of Eucalyptus melliodora. We also demonstrated a genetic basis for the phenotypic correlation underlying an ecological example of conditioned flavor aversion involving different biosynthetic pathways. Our results revealed that heritability estimates depend on the spatial scale of the analysis in a way that offers insight into the distribution of genetic and environmental variance. This study is the first to successfully use a marker-based method to measure quantitative genetic parameters in a tree. We suggest that this method will prove to be a useful tool in other studies and offer some recommendations for future applications of the method.

Andrew, R. L.; Peakall, R.; Wallis, I. R.; Wood, J. T.; Knight, E. J.; Foley, W. J.

2005-01-01

192

Integration of physical and genetic maps of common bean through BAC-derived microsatellite markers  

PubMed Central

Background Common bean (Phaseolus vulgaris L.) is the most important legume for direct human consumption and the goal of this study was to integrate a recently constructed physical map for the species with a microsatellite based genetic map using a BAC library from the genotype G19833 and the recombinant inbred line population DOR364 × G19833. Results We searched for simple sequence repeats (SSRs) in the 89,017 BAC-end sequences (BES) from the physical map and genetically mapped any polymorphic BES-SSRs onto the genetic map. Among the BES it was possible to identify 623 contig-linked SSRs, most of which were highly AT-rich. A subgroup of 230 di-nucleotide and tri-nucleotide based SSR primer pairs from these BACs was tested on the mapping parents with 176 single copy loci and 114 found to be polymorphic markers. Of these, 99 were successfully integrated into the genetic map. The 99 linkages between the genetic and physical maps corresponded to an equal number of contigs containing a total of 5,055 BAC clones. Conclusions Class II microsatellites were more common in the BES than longer class I microsatellites. Both types of markers proved to be valuable for linking BAC clones to the genetic map and were successfully placed across all 11 linkage groups. The integration of common bean physical and genetic maps is an important part of comparative genome analysis and a prelude to positional cloning of agronomically important genes for this crop.

2010-01-01

193

Diversity arrays technology (DArT) markers in apple for genetic linkage maps.  

PubMed

Diversity Arrays Technology (DArT) provides a high-throughput whole-genome genotyping platform for the detection and scoring of hundreds of polymorphic loci without any need for prior sequence information. The work presented here details the development and performance of a DArT genotyping array for apple. This is the first paper on DArT in horticultural trees. Genetic mapping of DArT markers in two mapping populations and their integration with other marker types showed that DArT is a powerful high-throughput method for obtaining accurate and reproducible marker data, despite the low cost per data point. This method appears to be suitable for aligning the genetic maps of different segregating populations. The standard complexity reduction method, based on the methylation-sensitive PstI restriction enzyme, resulted in a high frequency of markers, although there was 52-54% redundancy due to the repeated sampling of highly similar sequences. Sequencing of the marker clones showed that they are significantly enriched for low-copy, genic regions. The genome coverage using the standard method was 55-76%. For improved genome coverage, an alternative complexity reduction method was examined, which resulted in less redundancy and additional segregating markers. The DArT markers proved to be of high quality and were very suitable for genetic mapping at low cost for the apple, providing moderate genome coverage. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11032-011-9579-5) contains supplementary material, which is available to authorized users. PMID:22408382

Schouten, Henk J; van de Weg, W Eric; Carling, Jason; Khan, Sabaz Ali; McKay, Steven J; van Kaauwen, Martijn P W; Wittenberg, Alexander H J; Koehorst-van Putten, Herma J J; Noordijk, Yolanda; Gao, Zhongshan; Rees, D Jasper G; Van Dyk, Maria M; Jaccoud, Damian; Considine, Michael J; Kilian, Andrzej

2011-05-15

194

Influence of conserved and hypervariable genetic markers on genotyping circulating strains of Neisseria gonorrhoeae.  

PubMed

Presently there is no vaccine against Neisseria gonorrhoeae and therefore accurate information on gonococcal transmission plays a crucial role for interventions designed to limit the spread of infections caused by this microorganism. We evaluated the impact of two different categories of genetic markers, (i) concatenated sequences of 10 housekeeping genes and (ii) hypervariable porB DNA sequences, on the genetic relatedness and subsequently on genotyping analysis of this human pathogen. Eighty gonococcal isolates from Canada, China, the US, Argentina, Venezuela and Chile, collected over different times, were analyzed. Our results show that the choice of genetic marker had a profound effect on the interpretation of genotyping results associated with N. gonorrhoeae. The concatenated sequences of the housekeeping genes preserved the genetic relatedness of closely related isolates, enabling detection of the predominant strains circulating within a community (Saskatchewan, Canada) over an extended period of time. In contrast, a genetic marker based on antigen gene, porB, may lead to a failure to detect these predominant circulating strains. Based on the analysis of the DNA sequences of the 10 housekeeping genes, we identified two major clonal complexes, CC33 and CC22, which comprised STs from China, and Argentina as well as two STs from Canada. Several minor clonal complexes were observed among isolates from Saskatchewan. eBURST analysis suggested that the majority of the tested gonococcal isolates from Saskatchewan, Canada were endemic, with only a couple of genotypes introduced. PMID:22163288

Vidovic, Sinisa; Horsman, Greg B; Liao, Mingmin; Dillon, Jo-Anne R

2011-12-07

195

Incidence of the main genetic markers in glioblastoma multiforme is independent of tumor topology.  

PubMed

Glioblastoma multiforme (GBM) is the most common as well as the most aggressive type of primary brain tumor of astrocytic origin in adults. GBM is characterized by a high degree of intratumoral heterogeneity both in histomorphology and genetic changes. Trisomy/polysomy of chromosome 7, monosomy of chromosome 10, EGFR gene amplification and p53 deletion have been described as the typical genetic markers for tumor classification and prediction of possible response to therapy. Our work was based on detection of these four main genetic changes both in central and peripheral parts of the tumors to evaluate possible differences in the topological incidence of these genetic markers. Chromosomal abnormalities in tumor samples from a group of 21 patients surgically treated for GBM were characterized by means of the interphase-fluorescence in situ hybridization (I-FISH) technique using sets of centromere and locus-specific DNA probes. In addition, we performed a detailed analysis of one selected tumor sample using a genomic microarray system (GenoSensor Array 300) to characterize copy number changes of specific sequences and refine results obtained by I-FISH. However, the data show no significant differences in occurrence of the described genetic markers in either part of the tumor. PMID:17447852

Necesalová, E; Vranová, V; Kuglík, P; Cejpek, P; Jarosová, M; Pesáková, M; Relichová, J; Veselská, R

2007-01-01

196

Utility and efficiency of linked marker genes for genetic counseling. III. Proportion of informative families under linkage disequilibrium.  

PubMed Central

A marker locus closely linked to a disease locus is often useful for genetic counseling provided that a counselee is heterozygous at both disease and marker loci. Furthermore, the linkage phase of these genes in the counselee must be known. When the linkage between the disease and marker loci is very close, one often finds linkage disequilibrium between the loci. To evaluate the effect of such nonrandom associations on the utility of linked marker genes for genetic counseling, the proportion of informative families is studied for X-linked recessive and autosomal dominant diseases. This proportion is higher for X-linked genes than for autosomal genes, if other factors are the same. In general, codominant markers are more useful than dominant markers. Also, under appropriate conditions, the proportion of informative families is higher when linkage disequilibrium is present. The results obtained in this paper are useful for evaluating the utility of polymorphic restriction endonuclease cleavage sites as markers in genetic counseling.

Chakravarti, A

1983-01-01

197

Epigenetic-Genetic Chromosome Dosage Approach for Fetal Trisomy 21 Detection Using an Autosomal Genetic Reference Marker  

PubMed Central

Background The putative promoter of the holocarboxylase synthetase (HLCS) gene on chromosome 21 is hypermethylated in placental tissues and could be detected as a fetal-specific DNA marker in maternal plasma. Detection of fetal trisomy 21 (T21) has been demonstrated by an epigenetic-genetic chromosome dosage approach where the amount of hypermethylated HLCS in maternal plasma is normalized using a fetal genetic marker on the Y chromosome as a chromosome dosage reference marker. We explore if this method can be applied on both male and female fetuses with the use of a paternally-inherited fetal single nucleotide polymorphism (SNP) allele on a reference chromosome for chromosome dosage normalization. Methodology We quantified hypermethylated HLCS molecules using methylation-sensitive restriction endonuclease digestion followed by real-time or digital PCR analyses. For chromosome dosage analysis, we compared the amount of digestion-resistant HLCS to that of a SNP allele (rs6636, a C/G SNP) that the fetus has inherited from the father but absent in the pregnant mother. Principal Findings Using a fetal-specific SNP allele on a reference chromosome, we analyzed 20 euploid and nine T21 placental tissue samples. All samples with the fetal-specific C allele were correctly classified. One sample from each of the euploid and T21 groups were misclassified when the fetal-specific G allele was used as the reference marker. We then analyzed 33 euploid and 14 T21 maternal plasma samples. All but one sample from each of the euploid and T21 groups were correctly classified using the fetal-specific C allele, while correct classification was achieved for all samples using the fetal-specific G allele as the reference marker. Conclusions As a proof-of-concept study, we have demonstrated that the epigenetic-genetic chromosome dosage approach can be applied to the prenatal diagnosis of trisomy 21 for both male and female fetuses.

Tong, Yu K.; Chiu, Rossa W. K.; Akolekar, Ranjit; Leung, Tak Y.; Lau, Tze K.; Nicolaides, Kypros H.; Lo, Y. M. Dennis

2010-01-01

198

Construction of a high-throughput rat genetic mapping system with 466 arbitrarily primed-representational difference analysis markers  

Microsoft Academic Search

.   Linkage mapping of quantitative trait loci (QTLs) requires genetic markers that can be efficiently genotyped for a large\\u000a number of individuals. To isolate genetic markers suitable for this purpose, we previously established the arbitrarily primed\\u000a RDA (AP-RDA) method. Dot-blotting AP-PCR products (AP-amplicons) onto filters at a high density and hybridization of the filters\\u000a with the AP-RDA markers made it

Satoshi Yamashita; Yukinari Yoshida; Ayako Kurahashi; Takashi Sugimura; Toshikazu Ushijima

2000-01-01

199

Analysis on genetic diversity and genetic structure of Brasenia schreberi in Jiangsu and Zhejiang Provinces revealed by ISSR Markers  

Microsoft Academic Search

In order to investigate the level of genetic diversity of the endangered species Brasenia schreberi, three populations from Jiangsu and Zhejiang Provinces were sampled and analyzed using inter-simple sequence repeats (ISSR) markers. A total of fifty-four individuals were sampled. Twelve filtrated from 77 ISSR primers gave rise to 101 discernible DAN fragments of which 16 were polymorphic (15.84%). The average

ZHANG Guangfu; GAO Bangquan

2008-01-01

200

Construction of intersubspecific molecular genetic map of lentil based on ISSR, RAPD and SSR markers.  

PubMed

Lentil (Lens culinaris ssp. culinaris), is a self-pollinating diploid (2n = 2x = 14), cool-season legume crop and is consumed worldwide as a rich source of protein (~24.0%), largely in vegetarian diets. Here we report development of a genetic linkage map of Lens using 114 F(2) plants derived from the intersubspecific cross between L 830 and ILWL 77. RAPD (random amplified polymorphic DNA) primers revealed more polymorphism than ISSR (intersimple sequence repeat) and SSR (simple sequence repeat) markers. The highest proportion (30.72%) of segregation distortion was observed in RAPD markers. Of the 235 markers (34 SSR, 9 ISSR and 192 RAPD) used in the mapping study, 199 (28 SSRs, 9 ISSRs and 162 RAPDs) were mapped into 11 linkage groups (LGs), varying between 17.3 and 433.8 cM and covering 3843.4 cM, with an average marker spacing of 19.3 cM. Linkage analysis revealed nine major groups with 15 or more markers each and two small LGs with two markers each, and 36 unlinked markers. The study reported assigning of 11 new SSRs on the linkage map. Of the 66 markers with aberrant segregation, 14 were unlinked and the remaining 52 were mapped. ISSR and RAPD markers were found to be useful in map construction and saturation. The current map represents maximum coverage of lentil genome and could be used for identification of QTL regions linked to agronomic traits, and for marker-assisted selection in lentil. PMID:23271013

Gupta, Mamta; Verma, Bhawna; Kumar, Naresh; Chahota, Rakesh K; Rathour, Rajeev; Sharma, Shyam K; Bhatia, Sabhyata; Sharma, Tilak R

2012-12-01

201

Identifying genetic marker sets associated with phenotypes via an efficient adaptive score test.  

PubMed

In recent years, genome-wide association studies (GWAS) and gene-expression profiling have generated a large number of valuable datasets for assessing how genetic variations are related to disease outcomes. With such datasets, it is often of interest to assess the overall effect of a set of genetic markers, assembled based on biological knowledge. Genetic marker-set analyses have been advocated as more reliable and powerful approaches compared with the traditional marginal approaches (Curtis and others, 2005. Pathways to the analysis of microarray data. TRENDS in Biotechnology 23, 429-435; Efroni and others, 2007. Identification of key processes underlying cancer phenotypes using biologic pathway analysis. PLoS One 2, 425). Procedures for testing the overall effect of a marker-set have been actively studied in recent years. For example, score tests derived under an Empirical Bayes (EB) framework (Liu and others, 2007. Semiparametric regression of multidimensional genetic pathway data: least-squares kernel machines and linear mixed models. Biometrics 63, 1079-1088; Liu and others, 2008. Estimation and testing for the effect of a genetic pathway on a disease outcome using logistic kernel machine regression via logistic mixed models. BMC bioinformatics 9, 292-2; Wu and others, 2010. Powerful SNP-set analysis for case-control genome-wide association studies. American Journal of Human Genetics 86, 929) have been proposed as powerful alternatives to the standard Rao score test (Rao, 1948. Large sample tests of statistical hypotheses concerning several parameters with applications to problems of estimation. Mathematical Proceedings of the Cambridge Philosophical Society, 44, 50-57). The advantages of these EB-based tests are most apparent when the markers are correlated, due to the reduction in the degrees of freedom. In this paper, we propose an adaptive score test which up- or down-weights the contributions from each member of the marker-set based on the Z-scores of their effects. Such an adaptive procedure gains power over the existing procedures when the signal is sparse and the correlation among the markers is weak. By combining evidence from both the EB-based score test and the adaptive test, we further construct an omnibus test that attains good power in most settings. The null distributions of the proposed test statistics can be approximated well either via simple perturbation procedures or via distributional approximations. Through extensive simulation studies, we demonstrate that the proposed procedures perform well in finite samples. We apply the tests to a breast cancer genetic study to assess the overall effect of the FGFR2 gene on breast cancer risk. PMID:22734045

Cai, Tianxi; Lin, Xihong; Carroll, Raymond J

2012-06-25

202

Genetic Characterization of Five Hatchery Populations of the Pacific Abalone (Haliotis discus hannai) Using Microsatellite Markers  

PubMed Central

The Pacific abalone, Haliotis discus hannai, is a popular food in Eastern Asia. Aquacultural production of this species has increased because of recent resource declines, the growing consumption, and ongoing government-operated stock release programs. Therefore, the genetic characterization of hatchery populations is necessary to maintain the genetic diversity of this species and to develop more effective aquaculture practices. We analyzed the genetic structures of five cultured populations in Korea using six microsatellite markers. The number of alleles per locus ranged from 15 to 64, with an average of 23.5. The mean observed and expected heterozygosities were 0.797 and 0.904, respectively. The inbreeding coefficient FIS ranged from 0.054 to 0.184 (mean FIS = 0.121 ± 0.056). The genetic differentiation across all populations was low but significant (overall FST = 0.009, P < 0.01). Pairwise multilocus FST tests, estimates of genetic distance, and phylogenetic and principal component analyses did not show a consistent relationship between geographic and genetic distances. These results could reflect extensive aquaculture, the exchange of breeds and eggs between hatcheries and/or genetic drift due to intensive breeding practices. Thus, for optimal resource management, the genetic variation of hatchery stocks should be monitored and inbreeding controlled within the abalone stocks that are being released every year. This genetic information will be useful for the management of both H. discus hannai fisheries and the aquaculture industry.

An, Hye Suck; Lee, Jang Wook; Kim, Hyun Chul; Myeong, Jeong-In

2011-01-01

203

Genetic characterization of the gypsy moth from China (Lepidoptera, Lymantriidae) using inter simple sequence repeats markers.  

PubMed

This study provides the first genetic characterization of the gypsy moth from China (Lymantriadispar), one of the most recognized pests of forests and ornamental trees in the world. We assessed genetic diversity and structure in eight geographic populations of gypsy moths from China using five polymorphic Inter simple sequence repeat markers, which produced reproducible banding patterns. We observed 102 polymorphic loci across the 176 individuals sampled. Overall genetic diversity (Nei's, H) was 0.2357, while the mean genetic diversity within geographic populations was 0.1845 ± 0.0150. The observed genetic distance among the eight populations ranged from 0.0432 to 0.1034. Clustering analysis (using an unweighted pair-group method with arithmetic mean and multidimensional scaling), revealed strong concordance between the strength of genetic relationships among populations and their geographic proximity. Analysis of molecular variance demonstrated that 25.43% of the total variability (F ST = 0.2543, P < 0.001) was attributable to variation among geographic populations. The results of our analyses investigating the degree of polymorphism, genetic diversity (Nei's and Shannon) and genetic structure, suggest that individuals from Hebei may be better able to adapt to different environments and to disperse to new habitats. This study provides crucial genetic information needed to assess the distribution and population dynamics of this important pest species of global concern. PMID:23951339

Chen, Fang; Shi, Juan; Luo, You-Qing; Sun, Shuang-Yan; Pu, Min

2013-08-07

204

Analysis of genetic diversity in banana cultivars (Musa cvs.) from the South of Oman using AFLP markers and classification by phylogenetic, hierarchical clustering and principal component analyses*  

PubMed Central

Banana is an important crop grown in Oman and there is a dearth of information on its genetic diversity to assist in crop breeding and improvement programs. This study employed amplified fragment length polymorphism (AFLP) to investigate the genetic variation in local banana cultivars from the southern region of Oman. Using 12 primer combinations, a total of 1094 bands were scored, of which 1012 were polymorphic. Eighty-two unique markers were identified, which revealed the distinct separation of the seven cultivars. The results obtained show that AFLP can be used to differentiate the banana cultivars. Further classification by phylogenetic, hierarchical clustering and principal component analyses showed significant differences between the clusters found with molecular markers and those clusters created by previous studies using morphological analysis. Based on the analytical results, a consensus dendrogram of the banana cultivars is presented.

Opara, Umezuruike Linus; Jacobson, Dan; Al-Saady, Nadiya Abubakar

2010-01-01

205

Assessment of genetic diversity among Syrian durum (Triticum turgidum ssp. durum) and bread wheat (Triticum aestivum L.) using SSR markers.  

PubMed

Genetic diversity among 49 wheat varieties (37 durum and 12 bread wheat) was assayed using 32 microsatellites representing 34 loci covering almost the whole wheat genome. The polymorphic information content (PIC) across the tested loci ranged from 0 to 0.88 with average values of 0.57 and 0.65 for durum and bread wheat respectively. B genome had the highest mean number of alleles (10.91) followed by A genome (8.3) whereas D genome had the lowest number (4.73). The correlation between PIC and allele number was significant in all genome groups accounting for 0.87, 074 and 0.84 for A, B and D genomes respectively, and over all genomes, the correlation was higher in tetraploid (0.8) than in hexaploid wheat varieties (0.5). The cluster analysis discriminated all varieties and clearly divided the two ploidy levels into two separate clusters that reflect the differences in genetic diversity within each cluster. This study demonstrates that microsatellites markers have unique advantages compared to other molecular and biochemical fingerprinting techniques in revealing the genetic diversity in Syrian wheat varieties that is crucial for wheat improvement. PMID:21254727

Achtar, S; Moualla, M Y; Kalhout, A; Röder, M S; MirAli, N

2010-11-01

206

Small-scale field test of the genetically engineered lacZY marker  

SciTech Connect

Commercial genetic engineering is advancing into areas that require the small-scale introduction of genetically engineered microorganisms (GEMs) to better quantify variables that affect microorganism distribution and survival and to document potential long-term consequences. A recombinant DNA marker system, the lacZY marker, developed by the Monsanto Agricultural Co., enables the distribution and fate of marked fluorescent pseudomonad organisms to be monitored under actual field conditions. Critical evaluation of GEMs under field conditions is imperative if plant-beneficial effects are to be correlated with organism release. This paper evaluates the effectiveness of this marker system and its ability to facilitate the assessment of risks associated with deliberate environmental introductions of genetically engineered microorganisms. Results of prerelease contained growth chamber and field experiments demonstrated that: (1) the scientific risk assessment methodology adopted by Monsanto and approved by the U.S. Environmental Protection Agency was appropriate and comprehensive; (2) the deliberate introduction of a GEM did not pose unacceptable or unforeseen risks to human health or the environment; (3) the lacZY marker is an effective environmental tracking tool; and (4) regulatory oversight should reflect the expected risk and not be excessively burdensome for all GEMs.

Hattemer-Frey, H.A.; Brandt, E.J.; Travis, C.C. (Oak Ridge National Laboratory, TN (USA))

1990-06-01

207

Competitive Metagenomic DNA Hybridization Identifies Host-Specific Microbial Genetic Markers in Cow Fecal Samples†  

PubMed Central

Several PCR methods have recently been developed to identify fecal contamination in surface waters. In all cases, researchers have relied on one gene or one microorganism for selection of host-specific markers. Here we describe the application of a genome fragment enrichment (GFE) method to identify host-specific genetic markers from fecal microbial community DNA. As a proof of concept, bovine fecal DNA was challenged against a porcine fecal DNA background to select for bovine-specific DNA sequences. Bioinformatic analyses of 380 bovine enriched metagenomic sequences indicated a preponderance of Bacteroidales-like regions predicted to encode membrane-associated and secreted proteins. Oligonucleotide primers capable of annealing to select Bacteroidales-like bovine GFE sequences exhibited extremely high specificity (>99%) in PCR assays with total fecal DNAs from 279 different animal sources. These primers also demonstrated a broad distribution of corresponding genetic markers (81% positive) among 148 different bovine sources. These data demonstrate that direct metagenomic DNA analysis by the competitive solution hybridization approach described is an efficient method for identifying potentially useful fecal genetic markers and for characterizing differences between environmental microbial communities.

Shanks, Orin C.; Santo Domingo, Jorge W.; Lamendella, Regina; Kelty, Catherine A.; Graham, James E.

2006-01-01

208

Identification and genetic variation among Hibiscus species (Malvaceae) using RAPD markers.  

PubMed

Germplasm identification and characterization is an important link between the conservation and utilization of plant genetic resources. Traditionally, species or cultivars identification has relied on morphological characters like growth habit or floral morphology like flower colour and other characteristics of the plant. Studies were undertaken for identification and determination of genetic variation within the two species of Hibiscus and 16 varieties of Hibiscus rosa-sinensis L. through random amplified polymorphic (RAPD) markers. Primer screening was made by using the DNA of variety "Prolific". Genetic analysis was made by using ten selected decamer primers. A total of 79 distinct DNA fragments ranging from 0.3 to 2.5 kb were amplified by using ten selected random decamer primers. The genetic similarity was evaluated on the basis of presence or absence of bands. The cluster analysis indicated that the 16 varieties and two species formed one cluster. The first major cluster consisted of three varieties and a second major cluster consisted of two species and 13 varieties. The genetic distance was very close within the varieties and also among the species. Thus, these RAPD markers have the potential for identification of species/varieties and characterization of genetic variation within the varieties. This is also helpful in Hibiscus breeding programs and provides a major input into conservation biology. PMID:16610229

Barik, Suvakanta; Senapati, Sunil Kumar; Aparajita, Subhashree; Mohapatra, Anuradha; Rout, Gyana Ranjan

209

Genetic diversity of Amaranthus species from the Indo-Gangetic plains revealed by RAPD analysis leading to the development of ecotype-specific SCAR marker.  

PubMed

Genetic diversity and relationships among 6 Amaranthus species from 8 phytogeographic regions of the Indo-Gangetic plains were analyzed using a random amplified polymorphic DNA (RAPD) marker. RAPD primers yielded a total of 262 amplicons, ranging from approximately 250 to approximately 3000 bp in size with an average of 13.1 amplicons per primer, of which 254 amplicons (96.94%) were polymorphic. The genetic similarity coefficient among all the Amaranthus species ranged from 0.16 to 0.97 with a mean similarity coefficient of 0.56, indicating that variation existed in the genetic diversity of different populations. In the unweighted pair group method with arithmetic average dendrogram, populations of the same species clustered together. A unique 1371-bp RAPD band specific for Amaranthus gangeticus (syn. tricolor) of a particular phytogeographic region was converted to a sequenced characterized amplified region (SCAR) marker. The translated marker sequence showed homology with hemagglutinin protein. This SCAR marker is potentially useful for germplasm conservation and identification of amaranth ecotype. PMID:19060233

Ray, Tui; Roy, Satyesh Chandra

2008-12-05

210

Genetic evolutionary taboo search for optimal marker placement in infrared patient setup  

NASA Astrophysics Data System (ADS)

In infrared patient setup adequate selection of the external fiducial configuration is required for compensating inner target displacements (target registration error, TRE). Genetic algorithms (GA) and taboo search (TS) were applied in a newly designed approach to optimal marker placement: the genetic evolutionary taboo search (GETS) algorithm. In the GETS paradigm, multiple solutions are simultaneously tested in a stochastic evolutionary scheme, where taboo-based decision making and adaptive memory guide the optimization process. The GETS algorithm was tested on a group of ten prostate patients, to be compared to standard optimization and to randomly selected configurations. The changes in the optimal marker configuration, when TRE is minimized for OARs, were specifically examined. Optimal GETS configurations ensured a 26.5% mean decrease in the TRE value, versus 19.4% for conventional quasi-Newton optimization. Common features in GETS marker configurations were highlighted in the dataset of ten patients, even when multiple runs of the stochastic algorithm were performed. Including OARs in TRE minimization did not considerably affect the spatial distribution of GETS marker configurations. In conclusion, the GETS algorithm proved to be highly effective in solving the optimal marker placement problem. Further work is needed to embed site-specific deformation models in the optimization process.

Riboldi, M.; Baroni, G.; Spadea, M. F.; Tagaste, B.; Garibaldi, C.; Cambria, R.; Orecchia, R.; Pedotti, A.

2007-09-01

211

Markers  

ERIC Educational Resources Information Center

Dry erase whiteboards come with toxic dry erase markers and toxic cleaning products. Dry erase markers labeled "nontoxic" are not free of toxic chemicals and can cause health problems. Children are especially vulnerable to environmental health hazards; moreover, schools commonly have problems with indoor air pollution, as they are more densely…

Healthy Schools Network, Inc., 2011

2011-01-01

212

Genetic markers of restenosis after coronary angioplasty and after stent implantation.  

PubMed

Apart from coronary artery bypass grafting, percutaneous transluminal coronary angioplasty (PTCA) and intracoronary stent placement are well established treatment strategies for CAD. Substantial differences exist in the mechanisms of restenosis between conventional PTCA and stenting. Arterial remodeling is the main contributor to lumen re-narrowing after PTCA, whereas neointimal hyperplasia is almost the sole mechanism of restenosis after stenting. Several reports have demonstrated that genetic factors may be involved in the pathogenesis of restenosis after PTCA and in-stent restenosis. In this review the candidate genes involved in the pathogenesis of restenosis are analyzed as potential genetic markers of restenosis after PTCA and in-stent restenosis. The I/D angiotensin-I converting enzyme gene polymorphism, gene polymorphisms of the endothelial nitric oxide synthase (Glu298Asp, -786T>C), the glycoprotein IIIa PlA1/A2 gene polymorphism, gene polymorphism of the estrogen (PvuII), allele 2 of the interleukin-1ra gene, and the GT repeats in heme oxygenase-1 gene promoter may be used as genetic markers for in-stent-restenosis. On the other hand, only the stromelysin-1 5A/6A gene polymorphism and allele 2 of the interleukin-1ra gene may be used as a genetic marker for restenosis after PTCA. PMID:15795709

Petrovic, Daniel; Peterlin, Borut

2005-03-24

213

Genetic diversity in bambara groundnut (Vigna subterranea (L.) Verdc) landraces revealed by AFLP markers.  

PubMed

Bambara groundnut (Vigna subterranea (L.) Verdc), an African indigenous legume, is popular in most parts of Africa. The present study was undertaken to establish genetic relationships among 16 cultivated bambara groundnut landraces using fluorescence-based amplified fragment length polymorphism (AFLP) markers. Seven selective primer combinations generated 504 amplification products, ranging from 50 to 400 bp. Several landrace-specific products were identified that could be effectively used to produce landrace-specific markers for identification purposes. On average, each primer combination generated 72 amplified products that were detectable by an ABI Prism 310 DNA sequencer. The polymorphisms obtained ranged from 68.0 to 98.0%, with an average of 84.0%. The primer pairs M-ACA + P-GCC and M-ACA + P-GGA produced more polymorphic fragments than any other primer pairs and were better at differentiating landraces. The dendrogram generated by the UPGMA (unweighted pair-group method with arithmetic averaging) grouped 16 landraces into 3 clusters, mainly according to their place of collection or geographic origin. DipC1995 and Malawi5 were the most genetically related landraces. AFLP analysis provided sufficient polymorphism to determine the amount of genetic diversity and to establish genetic relationships in bambara groundnut landraces. The results will help in the formulation of marker-assisted breeding in bambara groundnut. PMID:12502264

Massawe, F J; Dickinson, M; Roberts, J A; Azam-Ali, S N

2002-12-01

214

Physical mapping of genetic markers on the short arm of chromosome 5  

SciTech Connect

The deletion of the short arm of chromosome 5 is associated with the cri-du-chat syndrome. In addition, loss of this portion of a chromosome is a common cytogenetic marker in a number of malignancies. However, to date, no genes associated with these disorders have been identified. Physical maps are the first step in isolating causative genes, and genes involved in autosomal recessive disorders are now routinely mapped through the identification of linked markers. Extensive genetic maps based upon polymorphic short tandem repeats (STRs) have provided researchers with a large number of markers to which such disorders can be genetically mapped. However, the physical locations of many of these STRs have not been determined. Toward the goal of integrating the human genetic maps with the physical maps, a 5p somatic cell hybrid deletion mapping panel that was derived from patients with 5p deletions or translocations was used to physically map 47 STRs that have been used to construct genetic maps of 5p. These data will be useful in the localization of disease genes that map to 5p and may be involved in the etiology of the cri-du-chat syndrome. 26 refs., 1 fig.

Gersh, M.; Goodart, S.A.; Overhauser, J. [Thomas Jefferson Univ., Philadelphia, PA (United States)

1994-12-01

215

Analysis of genetic diversity in Larix gmelinii (Pinaceae) with RAPD and ISSR markers.  

PubMed

Dahurian larch (Larix gmelinii), a deciduous conifer, is the northernmost tree, native to eastern Siberia and nearby regions of China. We used growth traits and molecular markers to assess genetic variation in different L. gmelinii growing regions; 105 individual samples were collected from seven regions of the Qingshan Forestry Centre, Heilongjiang Province, China. The greatest genetic regional variation was seen in the Youhao area, based on coefficients of variation for tree height, diameter and volume (14.73, 28.25, and 55.27%, respectively). Analysis using molecular markers showed rich genetic diversity. The RAPD and ISSR methods both indicated that most variation came from within populations. The seven regions were divided into two groups (Daxing'an and Xiaoxing'an Mountain ranges) by RAPD cluster analysis: Tianchi, Xiaojiuya, Yuanjiang, and Taiping regions were placed in the first group at a genetic distance of 0.08; while the other regions were in the second group. The correlation between RAPD markers and geographical distance was significant, with a correlation coefficient of 0.752. PMID:23408406

Zhang, L; Zhang, H G; Li, X F

2013-01-24

216

Novel SSR markers from BAC-end sequences, DArT arrays and a comprehensive genetic map with 1,291 marker loci for chickpea (Cicer arietinum L.).  

PubMed

Chickpea (Cicer arietinum L.) is the third most important cool season food legume, cultivated in arid and semi-arid regions of the world. The goal of this study was to develop novel molecular markers such as microsatellite or simple sequence repeat (SSR) markers from bacterial artificial chromosome (BAC)-end sequences (BESs) and diversity arrays technology (DArT) markers, and to construct a high-density genetic map based on recombinant inbred line (RIL) population ICC 4958 (C. arietinum)×PI 489777 (C. reticulatum). A BAC-library comprising 55,680 clones was constructed and 46,270 BESs were generated. Mining of these BESs provided 6,845 SSRs, and primer pairs were designed for 1,344 SSRs. In parallel, DArT arrays with ca. 15,000 clones were developed, and 5,397 clones were found polymorphic among 94 genotypes tested. Screening of newly developed BES-SSR markers and DArT arrays on the parental genotypes of the RIL mapping population showed polymorphism with 253 BES-SSR markers and 675 DArT markers. Segregation data obtained for these polymorphic markers and 494 markers data compiled from published reports or collaborators were used for constructing the genetic map. As a result, a comprehensive genetic map comprising 1,291 markers on eight linkage groups (LGs) spanning a total of 845.56 cM distance was developed (http://cmap.icrisat.ac.in/cmap/sm/cp/thudi/). The number of markers per linkage group ranged from 68 (LG 8) to 218 (LG 3) with an average inter-marker distance of 0.65 cM. While the developed resource of molecular markers will be useful for genetic diversity, genetic mapping and molecular breeding applications, the comprehensive genetic map with integrated BES-SSR markers will facilitate its anchoring to the physical map (under construction) to accelerate map-based cloning of genes in chickpea and comparative genome evolution studies in legumes. PMID:22102885

Thudi, Mahendar; Bohra, Abhishek; Nayak, Spurthi N; Varghese, Nicy; Shah, Trushar M; Penmetsa, R Varma; Thirunavukkarasu, Nepolean; Gudipati, Srivani; Gaur, Pooran M; Kulwal, Pawan L; Upadhyaya, Hari D; Kavikishor, Polavarapu B; Winter, Peter; Kahl, Günter; Town, Christopher D; Kilian, Andrzej; Cook, Douglas R; Varshney, Rajeev K

2011-11-15

217

Novel SSR Markers from BAC-End Sequences, DArT Arrays and a Comprehensive Genetic Map with 1,291 Marker Loci for Chickpea (Cicer arietinum L.)  

PubMed Central

Chickpea (Cicer arietinum L.) is the third most important cool season food legume, cultivated in arid and semi-arid regions of the world. The goal of this study was to develop novel molecular markers such as microsatellite or simple sequence repeat (SSR) markers from bacterial artificial chromosome (BAC)-end sequences (BESs) and diversity arrays technology (DArT) markers, and to construct a high-density genetic map based on recombinant inbred line (RIL) population ICC 4958 (C. arietinum)×PI 489777 (C. reticulatum). A BAC-library comprising 55,680 clones was constructed and 46,270 BESs were generated. Mining of these BESs provided 6,845 SSRs, and primer pairs were designed for 1,344 SSRs. In parallel, DArT arrays with ca. 15,000 clones were developed, and 5,397 clones were found polymorphic among 94 genotypes tested. Screening of newly developed BES-SSR markers and DArT arrays on the parental genotypes of the RIL mapping population showed polymorphism with 253 BES-SSR markers and 675 DArT markers. Segregation data obtained for these polymorphic markers and 494 markers data compiled from published reports or collaborators were used for constructing the genetic map. As a result, a comprehensive genetic map comprising 1,291 markers on eight linkage groups (LGs) spanning a total of 845.56 cM distance was developed (http://cmap.icrisat.ac.in/cmap/sm/cp/thudi/). The number of markers per linkage group ranged from 68 (LG 8) to 218 (LG 3) with an average inter-marker distance of 0.65 cM. While the developed resource of molecular markers will be useful for genetic diversity, genetic mapping and molecular breeding applications, the comprehensive genetic map with integrated BES-SSR markers will facilitate its anchoring to the physical map (under construction) to accelerate map-based cloning of genes in chickpea and comparative genome evolution studies in legumes.

Nayak, Spurthi N.; Varghese, Nicy; Shah, Trushar M.; Penmetsa, R. Varma; Thirunavukkarasu, Nepolean; Gudipati, Srivani; Gaur, Pooran M.; Kulwal, Pawan L.; Upadhyaya, Hari D.; KaviKishor, Polavarapu B.; Winter, Peter; Kahl, Gunter; Town, Christopher D.; Kilian, Andrzej; Cook, Douglas R.; Varshney, Rajeev K.

2011-01-01

218

Unique genetic factors influence sensitivity to the rewarding and aversive effects of methamphetamine versus cocaine.  

PubMed

Genetic factors significantly influence addiction-related phenotypes. This is supported by the successful bidirectional selective breeding of two replicate sets of mouse lines for amount of methamphetamine consumed. Some of the same genetic factors that influence methamphetamine consumption have been previously found also to influence sensitivity to the conditioned rewarding and aversive effects of methamphetamine. The goal of the current studies was to determine if some of the same genetic factors influence sensitivity to the conditioned rewarding and aversive effects of cocaine. Cocaine conditioned reward was examined in methamphetamine high drinking and low drinking line mice using a conditioned place preference procedure and cocaine conditioned aversion was measured using a conditioned taste aversion procedure. In addition, a general sensitivity measure, locomotor stimulant response to cocaine, was assessed in these lines; previous data indicated no difference between the selected lines in sensitivity to methamphetamine-induced stimulation. In contrast to robust differences for methamphetamine, the methamphetamine high and low drinking lines did not differ in sensitivity to either the rewarding or aversive effects of cocaine. They also exhibited comparable sensitivity to cocaine-induced locomotor stimulation. These data suggest that the genetic factors that influence sensitivity to the conditioned rewarding and aversive effects of methamphetamine in these lines of mice do not influence sensitivity to these effects of cocaine. Thus, different genetic factors may influence risk for methamphetamine versus cocaine use. PMID:23994231

Gubner, Noah R; Reed, Cheryl; McKinnon, Carrie S; Phillips, Tamara J

2013-08-28

219

Genetic diversity analysis in Opal cotton hybrids based on SSR, ISSR, and RAPD markers.  

PubMed

Cotton is one of the most economically important crops in Iran; hybridization is a means to increase the genetic diversity and obtain new elite cultivars in this crop. We examined agronomic characteristics and molecular genetic diversity in the Opal cotton (Gossypium hirsutum) cultivar and in F(2) progenies. Ten homo-primers and seven hetero-primers of 26 RAPD primers produced 261 reproducible bands, with an average of 4.18 bands per primer and 22% polymorphism. The OPB12/OPH08 primer gave the highest effective number of alleles (N(E)), and the largest Shannon index (I), Nei's genetic diversity (H), and polymorphism information content (PIC) values. Some RAPD bands were present in the parental genotypes but were absent in their hybrids. Ten ISSR primers produced 206 reproducible bands, with 49.4% polymorphism. The UBC807 locus gave the highest N(E), I, H, and PIC values. Some ISSR bands occurred only in the parental genotype, while others were only present in the hybrid genotypes. Four microsatellite loci produced 12 alleles, ranging from 181 to 236 bp, with 54% polymorphism. The TMB1421 locus, with a monomorphic allele, was digested with three restriction enzymes (CAP-microsatellite) to evaluate sequence variations among samples. Association analysis between molecular markers and agronomic data revealed a significant correlation between ISSR-UBC807-1500 and yield. The Mantel test performed among the genetic distance matrices obtained from RAPD, ISSR and SSR showed a non-significant regression between RAPD versus ISSR and ISSR versus SSR, while RAPD versus SSR showed a significant regression; regression for ISSR and RAPD+ISSR+SSR combined data was also significant. Cluster analysis (UPGMA) based on these three types of molecular markers differentiated cotton genotypes and their progenies. Among the molecular markers, ISSR revealed more genetic variation among the genotypes. However, using all three types of molecular markers provided a better overall view of cotton genome polymorphism. PMID:23408413

Noormohammadi, Z; Hasheminejad-Ahangarani Farahani, Y; Sheidai, M; Ghasemzadeh-Baraki, S; Alishah, O

2013-01-30

220

Neural mechanisms in Williams syndrome: a unique window to genetic influences on cognition and behaviour  

Microsoft Academic Search

Williams syndrome, a rare disorder caused by hemizygous microdeletion of about 28 genes on chromosome 7q11.23, has long intrigued neuroscientists with its unique combination of striking behavioural abnormalities, such as hypersociability, and characteristic neurocognitive profile. Williams syndrome, therefore, raises fundamental questions about the neural mechanisms of social behaviour, the modularity of mind and brain development, and provides a privileged setting

Carolyn B. Mervis; Karen Faith Berman; Andreas Meyer-Lindenberg

2006-01-01

221

Comparative Genomic Hybridization Suggests a Unique Genetic Basis for Virulence of Bordetella hinzii  

Technology Transfer Automated Retrieval System (TEKTRAN)

Particular strains of Bordetella hinzii can induce mild to moderate respiratory disease in turkeys but potential virulence factors of this agent have not been identified, despite extensive characterization of virulence factors in several other Bordetella species. To elucidate the genetic basis for ...

222

Genetic diversity of two haploid markers in the Udegey population from southeastern Siberia.  

PubMed

The Udegeys are a small ethnic group who live along the tributaries of the Amur River Basin of southeastern Siberia in Russia. They are thought to speak a language belonging to a subdivision of the Tungusic-Manchu branch of the Altaic family. To understand the genetic features and genetic history of the Udegeys, we analyzed two haploid markers, mitochondrial DNA (mtDNA), and Y-chromosomal variation, in 51 individuals (including 21 males) from the Udegey population. In general, the Udegeys' mtDNA profiles revealed similarities to Siberians and other northeastern Asian populations, although a moderate European contribution was also detected. Interestingly, pairwise values of F(ST) and the MDS plots based on the mtDNA variation showed that the Orok and Nivkh inhabiting the very same region of the Udegey were significantly different from the Udegey, implying that they may have been isolated and undergone substantial genetic drift. The Udegeys were characterized by a high frequency (66.7%) of Y chromosome haplogroup C, indicating a close genetic relationship with Mongolians and Siberians. On the paternal side, however, very little admixture was observed between the Udegeys and Europeans. Thus, the combined haploid genetic markers of both mtDNA and the Y chromosome imply that the Udegeys are overall closest to Siberians and northeast Asians of the Altaic linguistic family, with a minor maternal contribution from the European part of the continent. PMID:19953529

Jin, Han-Jun; Kim, Ki-Cheol; Kim, Wook

2010-06-01

223

Genetic diversity and population structure of Indonesian native chickens based on single nucleotide polymorphism markers.  

PubMed

Indonesian native chickens are considered an important genetic resource, particularly with respect to their excellent traits for meat and egg production. However, few molecular genetic studies of these native chickens have been conducted. We analyzed the genetic diversity and differentiation of 4 populations of Indonesian native chickens: Black Kedu (BK), Kedu (KD), Kampung (LOC), and Arab (AR). Blood samples from 188 individuals were collected in central and western Java. Genomic DNA was genotyped using 98 autosomal SNP markers, of which 87 were found to be polymorphic. The proportion of polymorphic loci and the average heterozygosity of each population were in the range of 0.765 to 0.878 and 0.224 to 0.263, respectively. The 4 populations of Indonesian chickens appeared to be derived from 3 genetic populations (K = 3): maximum likelihood clustering showed that the BK variety and AR breed were each assigned to a distinct cluster, whereas the LOC ecotype and KD variety were admixed populations with similar proportions of membership. Principal components analysis revealed that eigenvector 1 separated BK and AR from the other 2 populations. Neighbor-joining trees constructed from pairwise distance matrix (F(ST)) estimates, for individuals and between populations, corroborated that the LOC ecotype and KD variety were related closely, whereas the BK variety and AR breed diverged at greater distances. These results also confirmed the usefulness of SNP markers for the study of genetic diversity. PMID:22010231

Riztyan; Katano, T; Shimogiri, T; Kawabe, K; Okamoto, S

2011-11-01

224

Uniqueness of polymorphism for a discrete, selection-migration model with genetic dominance  

Microsoft Academic Search

The migration into a natural population of a controlled popu- lation, e.g., a transgenic population, is studied using a one island selection-migration model. A 2-dimensional system of nonlinear dif- ference equations describes changes in allele frequency and population size between generations. Biologically reasonable conditions are ob- tained which guarantee the existence and uniqueness of a polymorphic equilibrium in the cases

James F. Selgrade; James H. Roberds

2009-01-01

225

Genetic Variability in Six Mexican Gray Wolf (Canis lupus baileyi) Populations Determined by Microsatellite Markers  

Microsoft Academic Search

Jaramillo-Jaimes, M.T., Sifuentes-Rincón, A.M., Sánchez Torres-Esqueda, M.T., Mendoza-Martínez, G.D., Clemente-Sánchez, F., Olivera-López, J.I., Molina Hernández, M. and Martínez-Tripp, S.C. 2007. Genetic variability in six Mexican gray wolf (Canis lupus baileyi) populations determined by microsatellite markers. J. Appl. Anim. Res., 31: 131–136.A study was conducted to evaluate genetic diversity in six Mexican gray wolf populations based on six microsatellite loci. Allelic

M. T. Jaramillo-Jaimes; A. M. Sifuentes-Rincón; M. T. Sánchez Torres-Esqueda; G. D. Mendoza-Martínez; F. Clemente-Sánchez; J. I. Olivera-López; M. Molina Hernández; S. C. Martínez-Tripp

2007-01-01

226

Genetic relationships among seven sections of genus Arachis studied by using SSR markers  

PubMed Central

Background The genus Arachis, originated in South America, is divided into nine taxonomical sections comprising of 80 species. Most of the Arachis species are diploids (2n = 2x = 20) and the tetraploid species (2n = 2x = 40) are found in sections Arachis, Extranervosae and Rhizomatosae. Diploid species have great potential to be used as resistance sources for agronomic traits like pests and diseases, drought related traits and different life cycle spans. Understanding of genetic relationships among wild species and between wild and cultivated species will be useful for enhanced utilization of wild species in improving cultivated germplasm. The present study was undertaken to evaluate genetic relationships among species (96 accessions) belonging to seven sections of Arachis by using simple sequence repeat (SSR) markers developed from Arachis hypogaea genomic library and gene sequences from related genera of Arachis. Results The average transferability rate of 101 SSR markers tested to section Arachis and six other sections was 81% and 59% respectively. Five markers (IPAHM 164, IPAHM 165, IPAHM 407a, IPAHM 409, and IPAHM 659) showed 100% transferability. Cluster analysis of allelic data from a subset of 32 SSR markers on 85 wild and 11 cultivated accessions grouped accessions according to their genome composition, sections and species to which they belong. A total of 109 species specific alleles were detected in different wild species, Arachis pusilla exhibited largest number of species specific alleles (15). Based on genetic distance analysis, the A-genome accession ICG 8200 (A. duranensis) and the B-genome accession ICG 8206 (A. ipaënsis) were found most closely related to A. hypogaea. Conclusion A set of cross species and cross section transferable SSR markers has been identified that will be useful for genetic studies of wild species of Arachis, including comparative genome mapping, germplasm analysis, population genetic structure and phylogenetic inferences among species. The present study provides strong support based on both genomic and genic markers, probably for the first time, on relationships of A. monticola and A. hypogaea as well as on the most probable donor of A and B-genomes of cultivated groundnut.

2010-01-01

227

Isolation and characterization of microsatellite markers and analysis of genetic variability in Curculigo latifolia Dryand.  

PubMed

Curculin, a sweet protein found in Curculigo latifolia fruit has great potential for the pharmaceutical industry. This protein interestingly has been found to have both sweet taste and taste-modifying capacities comparable with other natural sweeteners. According to our knowledge this is the first reported case on the isolation of microsatellite loci in this genus. Hence, the current development of microsatellite markers for C. latifolia will facilitate future population genetic studies and breeding programs for this valuable plant. In this study 11 microsatellite markers were developed using 3' and 5' ISSR markers. The primers were tested on 27 accessions from all states of Peninsular Malaysia. The number of alleles per locus ranged from three to seven, with allele size ranging from 141 to 306 bp. The observed and expected heterozygosity ranged between 0.00-0.65 and 0.38-0.79, respectively. The polymorphic information content ranged from 0.35 to 0.74 and the Shannon's information index ranged from 0.82 to 1.57. These developed polymorphic microsatellites were used for constructing a dendrogram by unweighted pair group method with arithmetic mean cluster analysis using the Dice's similarity coefficient. Accessions association according to their geographical origin was observed. Based on characteristics of isolated microsatellites for C. latifolia accessions all genotype can be distinguished using these 11 microsatellite markers. These polymorphic markers could also be applied to studies on uniformity determination and somaclonal variation of tissue culture plantlets, varieties identification, genetic diversity, analysis of phylogenetic relationship, genetic linkage maps and quantitative trait loci in C. latifolia. PMID:22752726

Babaei, Nahid; Abdullah, Nur Ashikin Psyquay; Saleh, Ghizan; Abdullah, Thohirah Lee

2012-06-30

228

Extensive Genetic Diversity, Unique Population Structure and Evidence of Genetic Exchange in the Sexually Transmitted Parasite Trichomonas vaginalis  

Microsoft Academic Search

BackgroundTrichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted infection world-wide. Despite its prevalence, little is known about the genetic diversity and population structure of this haploid parasite due to the lack of appropriate tools. The development of a panel of microsatellite makers and SNPs from mining the parasite's genome sequence has paved the

Melissa D. Conrad; Andrew W. Gorman; Julia A. Schillinger; Pier Luigi Fiori; Rossana Arroyo; Nancy Malla; Mohan Lal Dubey; Jorge Gonzalez; Susan Blank; William E. Secor; Jane M. Carlton

2012-01-01

229

Genetic structure of a Lima bean base collection using allozyme markers  

Microsoft Academic Search

Genetic diversity and structure within a Lima bean (Phaseolus lunatus L.) base collection have been evaluated using allozyme markers. The results obtained from the analysis of wild and cultivated\\u000a accessions confirm the existence of Andean and Mesoamerican gene pools characterised by specific alleles. Wild and cultivated\\u000a accessions of the same gene pool are grouped. The Andean natural populations have a

A. Maquet; I. Zoro Bi; M. Delvaux; B. Wathelet; J.-P. Baudoin

1997-01-01

230

Genetic diversity among Texas bluegrass genotypes (Poa arachnifera Torr.) revealed by AFLP and RAPD markers  

Microsoft Academic Search

Texas bluegrass Poa arachnifera Torr., is a vigorous sod-forming perennial, dioecious grass, tolerant to heat. It is native to the Southern Great Plains. Genetic\\u000a relationships existing among 28 Texas bluegrass genotypes were investigated using amplified fragment length polymorphism (AFLP)\\u000a and randomly amplified polymorphic DNA (RAPD). A total of 3756 AFLP markers were generated on the 28 genotypes of Texas bluegrass.

K. Renganayaki; J. C. Read; A. K. Fritz

2001-01-01

231

Analysis of genetic structure in a sample of coffee ( Coffea arabica L.) using fluorescent SSR markers  

Microsoft Academic Search

The knowledge of population structure is important to determine the degree of linkage disequilibrium, which allows the selection\\u000a of genotypes for association mapping. Using 47 SSR markers, the genetic variability and population structure of 68 accessions\\u000a of C. arabica (wild and cultivated) and of three diploid species used as reference were evaluated. The analysis was done with the distance\\u000a method

German López-Gartner; Hernando Cortina; Susan R. McCouch; Maria Del Pilar Moncada

2009-01-01

232

Assessment of genetic diversity and relationships among Coix lacryma-jobi accessions using microsatellite markers  

Microsoft Academic Search

The present study describes the assessment of genetic diversity and relationships among 79 Job’s tears (Coix lacrymajobi L.) accessions collected from China and Korea using 17 microsatellite markers. A total of 57 alleles were detected with an\\u000a average of 3.4 alleles per locus. A high frequency of rare alleles (36.3 %) was observed within the collection. Values for\\u000a observed (HO),

K.-H. Ma; K.-H. Kim; A. Dixit; I.-M. Chung; J.-G. Gwag; T.-S. Kim; Y.-J. Park

2010-01-01

233

Genetic characterisation of Mytilus galloprovincialis Lmk. in North West Africa using nuclear DNA markers  

Microsoft Academic Search

The genetic relationships among Mytilus galloprovincialis populations over their range in the northeastern Atlantic and the western Mediterranean were investigated using polymerase chain reaction (PCR)-amplified nuclear DNA markers. We used long-range polyacrylamide gel electrophoresis for characterising an intron-length polymorphism at the actin gene locus mac-1 in Mytilus. Sharp resolution was obtained with this technique, which revealed a high level of

Claire Daguin; Philippe Borsa

1999-01-01

234

Segregation of genetic markers among wheat doubled haploid lines derived from wheat x maize crosses  

Microsoft Academic Search

Wheat doubled haploid (DH) lines were produced from the F1 hybrid, Fukudo-komugi x Oligo Culm, through intergeneric crosses between wheat and maize. F2 plants and 203 DH lines were analyzed for the segregation of the eight genetic markers, namely, grain proteins, grain esterases, GA-insensitivity and glume traits. The segregation in the F2 plants fitted to the expected ratios. No deviation

Kazuhiro Suenaga; Kousuke Nakajima

1992-01-01

235

Microsatellite markers reveal high genetic diversity in date palm ( Phoenix dactylifera L.) germplasm from Sudan  

Microsoft Academic Search

Genetic diversity in date palm germplasm from Sudan representing 37 female and 23 male accessions was investigated using 16\\u000a loci of microsatellite (SSR) primers. Eight female accessions from Morocco were included as reference material. The tested\\u000a SSR markers showed a high level of polymorphism. A total of 343 alleles were detected at the 16 loci. The number of alleles\\u000a per

Sakina Elshibli; Helena Korpelainen

2008-01-01

236

New microsatellite markers for assessment of genetic diversity in date palm ( Phoenix dactylifera L.)  

Microsoft Academic Search

New primer pairs of genomic DNA microsatellite markers were tested to assess the genetic diversity of eleven date palm genotypes.\\u000a The results indicated that out of thirty, only seven primers (23.3%) failed to amplify the expected PCR fragments, while thirteen\\u000a primers (43.3%) amplified monomorphic banding patterns and the remaining ten primers (33.4%) generated polymorphic banding\\u000a patterns. A total of 77

Khaled Elmeer; Hina Sarwath; Joel Malek; Michael Baum; Aladdin Hamwieh

237

[Cloning goat producing human lactoferrin with genetically modified donor cells selected by single or dual markers].  

PubMed

We compared the efficiency of cloning goat using human lactoferrin (hLF) with genetically modified donor cells marked by single (Neo(r)) or double (Neo(r)/GFP) markers. Single marker expression vector (pBLC14) or dual markers expression vector (pAPLM) was delivered to goat fetal fibroblasts (GFF), and then the transgenic GFF was used as donor cells to produce transgenic goats. Respectively, 58.8% (20/34) and 86.7% (26/30) resistant cell lines confirmed the transgenic integration by PCR. Moreover, pAPLM cells lines were subcultured with several passages, only 20% (6/30) cell lines was observed fluorescence from each cell during the cell passage. Somatic cell nuclear transfer using the donor cells harbouring pBLC14 or pAPLM construct, resulting in a total of 806 reconstructed embryos, a pregnancy rate at 35 d (53.8%, 39.1%) and 60 d (26.9%, 21.7%), and an offspring birth rate (1.9%, 1.4%) with 5 and 7 newborn cloned goats, respectively. Transgene was confirmed by PCR and southern-blot in all cloned offspring. There were no significant differences at the reconstructed embryo fusion rates, pregnancy rates and the birth rate (P > 0.05) between single and double markers groups. The Neo(r)/GFP double markers could improve the reliability for accurately and efficiently selecting the genetically modified donor cells. No adverse effect was observed on the efficiency of transgenic goat production by SCNT using somatic cells transfected with double (Neo(r)/GFP) markers vector. PMID:23593872

An, Liyou; Yuan, Yuguo; Yu, Baoli; Yang, Tingjia; Cheng, Yong

2012-12-01

238

Genetic relationships in the peregrine falcon (Falco peregrinus) analysed by microsatellite DNA markers.  

PubMed

Microsatellite DNA markers were developed from a peregrine falcon (Falco peregrinus) and genetic relationships among peregrine falcons in southern Norway were analysed using the markers. The genomic DNA library was screened for the presence of dinucleotide microsatellite repeats. Twelve loci revealed polymorphism through the initial analysis of 24 unrelated peregrine falcons, and Mendelian inheritance was confirmed in two peregrine falcon families bred in captivity. The estimated mean probability of identical genotypes in two unrelated individuals was 3 x 10-8, and the combined exclusion probability for parentage testing was 0.99 and 0.94 for one or both parents unknown, respectively. The markers were used to investigate the parentage of peregrine broods from the same nest site from different breeding seasons, and subsequently the nest-site fidelity of the breeding peregrines. High nest-site fidelity was found by studying pairwise comparisons of relatedness (rxy) estimates among chicks at six nest sites from three different breeding seasons. Cross-species amplifications showed that most loci also appeared to amplify polymorphic products in the gyrfalcon (F. rusticolus), merlin (F. columbarius), hobby (F. subbuteo) and kestrel (F. tinnunculus), demonstrating that the loci will provide powerful genetic markers in these falcons too. PMID:10652075

Nesje, M; Røed, K H; Lifjeld, J T; Lindberg, P; Steen, O F

2000-01-01

239

Correlation between molecular markers and adaptively significant genetic variation in Bromus tectorum (Poaceae), an inbreedingannual grass.  

PubMed

Single sequence repeat (SSR) and amplified fragment length polymorphic (AFLP) molecular marker genotypes in cheatgrass (Bromus tectorum) were compared to published data on phenotypic variation in seed dormancy, vernalization requirement, and resistance to the pathogen Ustilago bullata. Several features of cheatgrass facilitated this study: it is a recent invader in the western United States, has considerable phenotypic polymorphism, and is an obligate self-pollinator. Forty self-pollinating lines from four populations common to the three phenotypic data sets were analyzed for molecular genetic variation using seven SSR loci and 31 AFLP loci. We examined correlations between distance matrices using the Mantel test for each pair of studies. The two molecular data sets were significantly correlated (r = 0.636). The AFLP markers often distinguished among several lines with identical SSR genotypes. The AFLP data were also significantly correlated with the phenotypic data (r values from 0.4640 to 0.5658), but the SSR data were much more highly correlated (r values from 0.677 to 0.844). The difference between molecular marker systems was especially notable when an outlier population from Potosi Pass, Nevada, was excluded from the analysis. These results suggest that SSR markers may be good surrogates for phenotypic traits in population genetic studies of strongly inbreeding species such as cheatgrass. PMID:21653434

Ramakrishnan, Alisa P; Meyer, Susan E; Waters, Jennifer; Stevens, Mikel R; Coleman, Craig E; Fairbanks, Daniel J

2004-06-01

240

Analysis of the transcriptome of Panax notoginseng root uncovers putative triterpene saponin-biosynthetic genes and genetic markers  

PubMed Central

Background Panax notoginseng (Burk) F.H. Chen is important medicinal plant of the Araliacease family. Triterpene saponins are the bioactive constituents in P. notoginseng. However, available genomic information regarding this plant is limited. Moreover, details of triterpene saponin biosynthesis in the Panax species are largely unknown. Results Using the 454 pyrosequencing technology, a one-quarter GS FLX titanium run resulted in 188,185 reads with an average length of 410 bases for P. notoginseng root. These reads were processed and assembled by 454 GS De Novo Assembler software into 30,852 unique sequences. A total of 70.2% of unique sequences were annotated by Basic Local Alignment Search Tool (BLAST) similarity searches against public sequence databases. The Kyoto Encyclopedia of Genes and Genomes (KEGG) assignment discovered 41 unique sequences representing 11 genes involved in triterpene saponin backbone biosynthesis in the 454-EST dataset. In particular, the transcript encoding dammarenediol synthase (DS), which is the first committed enzyme in the biosynthetic pathway of major triterpene saponins, is highly expressed in the root of four-year-old P. notoginseng. It is worth emphasizing that the candidate cytochrome P450 (Pn02132 and Pn00158) and UDP-glycosyltransferase (Pn00082) gene most likely to be involved in hydroxylation or glycosylation of aglycones for triterpene saponin biosynthesis were discovered from 174 cytochrome P450s and 242 glycosyltransferases by phylogenetic analysis, respectively. Putative transcription factors were detected in 906 unique sequences, including Myb, homeobox, WRKY, basic helix-loop-helix (bHLH), and other family proteins. Additionally, a total of 2,772 simple sequence repeat (SSR) were identified from 2,361 unique sequences, of which, di-nucleotide motifs were the most abundant motif. Conclusion This study is the first to present a large-scale EST dataset for P. notoginseng root acquired by next-generation sequencing (NGS) technology. The candidate genes involved in triterpene saponin biosynthesis, including the putative CYP450s and UGTs, were obtained in this study. Additionally, the identification of SSRs provided plenty of genetic makers for molecular breeding and genetics applications in this species. These data will provide information on gene discovery, transcriptional regulation and marker-assisted selection for P. notoginseng. The dataset establishes an important foundation for the study with the purpose of ensuring adequate drug resources for this species.

2011-01-01

241

Genetic flanking markers refine diagnostic criteria and provide insights into the genetics of Von Hippel Lindau disease.  

PubMed Central

Von Hippel Lindau disease (VHL) is a hereditary syndrome, associated with tumors and cysts in multiple organ systems, whose expression and age of onset are highly variable. The availability of a genetic test for the early and reliable detection of individuals carrying the defective gene would be beneficial for VHL patients and their relatives, since many of the manifestations of VHL can be successfully treated if detected in their early stages, while the complications of undetected disease can be devastating. We have previously shown that the VHL gene maps to chromosome 3p. To provide genetic markers for the development of a reliable diagnostic test, and to further narrow and eventually clone the VHL defect, we have generated DNA markers for chromosome 3p. With these markers, we have performed a multipoint genetic linkage analysis in 28 VHL pedigrees, comprising 470 individuals, 164 of whom were affected with VHL. Here we report the identification of tightly linked markers, including flanking markers that bracket the VHL gene to a small region on chromosome 3p25-p26. This finding has several major implications. While visceral cysts of the kidney, pancreas, and epididymis are commonly found in VHL and are considered diagnostic criteria for this disorder, they also occur in the general population. The presence of cysts, unaccompanied by other more typical lesions such as retinal and cerebellar hemangioblastoma, may therefore represent a major diagnostic problem, leading to errors in the assessment of disease status. The application of flanking markers for the VHL gene for presymptomatic diagnostic testing confirms that epididymal cysts are indeed not suitable as a diagnostic criterion in this disorder. Pheochromocytomas occur nonuniformly in VHL families and may also be associated with other hereditary tumor syndromes; our genetic studies imply that the phenotype in VHL families with and without pheochromocytomas is caused by defects within the same gene. The absence or presence of this tumor type is therefore due to the pleiotropic expression of a single gene rather than to the existence of several different genes for VHL. The region on chromosome 3p13-p14 known to contain several chromosomal translocation breakpoints in families with "pure familial renal cell carcinoma" is quite proximal to the VHL locus in 3p25-p26 we have identified. Chromosome 3p may therefore contain two loci for renal cell carcinoma: one gene (or genes) in 3p13-p14 and the VHL gene in 3p25-p26, whose aberration is also associated with other typical manifestations of VHL. Since renal cell carcinoma, pheochromocytoma, and visceral cysts can occur sporadically even in young people and may also be associated with other tumor syndromes, the availability of flanking markers for the VHL gene will be useful in identifying VHL gene carriers, particularly among those individuals at risk in whom these are the only manifestations of disease. The isolation and characterization of the VHL gene, based on the identification of flanking markers, will have important implications for diagnosis and treatment of patients with VHL, as well as for a much larger number of individuals having the sporadic counterparts of VHL-associated tumor types.

Seizinger, B R; Smith, D I; Filling-Katz, M R; Neumann, H; Green, J S; Choyke, P L; Anderson, K M; Freiman, R N; Klauck, S M; Whaley, J

1991-01-01

242

Epidemiological association of Campylobacter jejuni groups with pathogenicity-associated genetic markers  

PubMed Central

Background Campylobacter jejuni, the most leading cause for bacterial gastroenteritis worldwide, shows a high genetic diversity among its isolates. Recently, we demonstrated the existence of six C. jejuni-groups by combining MLST with six genetic markers. These groups were further characterized by the detection of cj1321-cj1326, fucP, cj0178, cj0755/cfrA, ceuE, pldA, cstII, and cstIII in order (I.) to show further associations between these different genetic markers and MLST CCs. Moreover, different studies were able to associate several of these markers: a sialylated lipoologosaccharide (cstII/III+), the gamma-glytamyl-transpeptidase (ggt+), and the absence of a certain allele of the enterochelin-uptake-binding-protein (ceuE11168-) with severe campylobacteriosis, bloody diarrhea and unpleasant outcome. Additionally more than half of human Campylobacter-isolates were assigned to a non-livestock clade associated with the absence of cj1321-cj1326. These isolates were considered as mere colonizers. From the combination of marker genes, the ratio of human isolates in a specific group, and clinical data (II.) it should be demonstrated to which of the previous defined groups these Campylobacter-subpopulations, associated with higher virulence, correspond. Results Besides the marker gene pldA, all new estimated genetic markers show significant differences in their distribution among the various MLST-based groups. Especially the genes for cj1321-cj1326, fucP, cj0178, cj0755/cfrA are widely associated with each other and split the study population into two major and seven intermediate groups substantiating the previous group-definition, whereas cstII and cstIII indicate at least three groups following an independent distribution pattern. Conclusions Based on these data a group of C. jejuni-isolates characterized by the presence of ansB, dmsA, ggt, and the absence of cj1365c, cj1585c, cj1321-cj1326, fucP, cj0178, cj0755/cfrA, and cstII/III was associated with a higher prevalence in human campylobacteriosis, bloody diarrhea as well as hospitalization and bears obviously a higher virulence for humans. In contrast to that better livestock-adapted groups characterized by the ability to utilize L-fucose and the presence of all of the five identified putative C. jejuni iron-uptake systems as well as cj1321-cj1326, cj1365c, cj1585c, and cstII and/or cstIII (sialylated lipoologosaccharide) is more prevalent in animal hosts and was secondary associated with less severe campylobacteriosis.

2012-01-01

243

Identification of genetic markers linked to anthracnose resistance in sorghum using association analysis.  

PubMed

Anthracnose in sorghum caused by Colletotrichum sublineolum is one of the most destructive diseases affecting sorghum production under warm and humid conditions. Markers and genes linked to resistance to the disease are important for plant breeding. Using 14,739 SNP markers, we have mapped eight loci linked to resistance in sorghum through association analysis of a sorghum mini-core collection consisting of 242 diverse accessions evaluated for anthracnose resistance for 2 years in the field. The mini-core was representative of the International Crops Research Institute for the Semi-Arid Tropics' world-wide sorghum landrace collection. Eight marker loci were associated with anthracnose resistance in both years. Except locus 8, disease resistance-related genes were found in all loci based on their physical distance from linked SNP markers. These include two NB-ARC class of R genes on chromosome 10 that were partially homologous to the rice blast resistance gene Pib, two hypersensitive response-related genes: autophagy-related protein 3 on chromosome 1 and 4 harpin-induced 1 (Hin1) homologs on chromosome 8, a RAV transcription factor that is also part of R gene pathway, an oxysterol-binding protein that functions in the non-specific host resistance, and homologs of menthone:neomenthol reductase (MNR) that catalyzes a menthone reduction to produce the antimicrobial neomenthol. These genes and markers may be developed into molecular tools for genetic improvement of anthracnose resistance in sorghum. PMID:23463493

Upadhyaya, Hari D; Wang, Yi-Hong; Sharma, Rajan; Sharma, Shivali

2013-03-06

244

[Genetic variability of Siberian fir (Abies sibirica Ledeb.) inferred from AFLP markers].  

PubMed

Genetic variability of AFLP markers was studied in 20 populations of Siberian fir (Abies sibirica (Pinaceae) and in two populations of Far-Eastern Manchurian fir A. nephrolepis and Sakhalin fir A. sachalinensis each. Four pairs of selective primers were used. In total, 168 samples from three fir species were genotyped for 117 polymorphic loci. According to the AMOVA results, the variability proportion characterizing the differences between three Abies species was several times higher (F(CT) = 0.53) than that accounting for among-population differences within the species (F(SC) = 0.125). Differentiation of the A. sibirica populations based on AFLP markers exceeded 14% (F(ST) = 0.141). Significant correlation between the genetic distances calculated from the AFLP data and the geographic distances between populations was found. The results of AFLP variability analysis supported and supplemented the conclusions inferred previously from allozyme and cpSSR data: several genetically similar geographic groups of Siberian fir were identified. These groups differ both in allele frequencies and in the levels of genetic variation. PMID:21516799

Semerikova, S A; Semerikov, V L

2011-02-01

245

Pseudoterranova decipiens species A and B (Nematoda, Ascaridoidea): nomenclatural designation, morphological diagnostic characters and genetic markers.  

PubMed

Five genetically distinct and reproductively isolated species have been detected previously within the morphospecies Pseudoterranova decipiens from the Arctic-Boreal, Boreal and Antarctic. Morphological analysis was carried out on male specimens identified by genetic (allozyme) markers, allowing the detection of significant differences at a number of characters between two members of the P. decipiens complex, namely P. decipiens A and B. On the basis of such differences, the nomenclatural designation for the two species is discussed. The names Pseudoterranova krabbei n. sp. and P. decipiens (sensu stricto) are proposed for species A and B, respectively. Morphological and genetic differentiation between the two species is shown using multivariate analysis. Allozyme diagnostic keys for routine identification of the four members of the P. decipiens complex, namely P. decipiens (s.s.), P. krabbei, P. bulbosa and P. azarasi, irrespective of sex and life-history stage, are provided. PMID:10768762

Paggi, L; Mattiucci, S; Gibson, D I; Berland, B; Nascetti, G; Cianchi, R; Bullini, L

2000-03-01

246

Selected Genetic Markers of Blood and Secretions for Youths, 12-17 Years of Age, United States.  

National Technical Information Service (NTIS)

Percentage distributions of nine genetic markers, including ABO blood type, secretor ability, haptoglobin type, transferrin type, and group specific component type, are presented and discussed by age, sex, race, geographic region, family income and parent...

B. H. Cohen W. B. Bias P. V. V. Hamill T. A. Drizd E. L. Diamond

1980-01-01

247

Genetic succession and spatial genetic structure in a natural old growth Cryptomeria japonica forest revealed by nuclear and chloroplast microsatellite markers  

Microsoft Academic Search

Spatial genetic structure and diversity of Cryptomeria japonica trees in old growth forest but selectively logged in approximately 300 years ago were analyzed using seven nuclear microsatellite markers and one chloroplast microsatellite marker. The individuals were sampled from a 4-ha natural forest plot (200m×200m), which are consisted of three size classes including newly regenerated individuals such as regenerated individuals (REG

Tomokazu Takahashi; Naoki Tani; Kaoru Niiyama; Shigejiro Yoshida; Hideaki Taira; Yoshihiko Tsumura

2008-01-01

248

Transcriptome Sequencing of Hevea brasiliensis for Development of Microsatellite Markers and Construction of a Genetic Linkage Map  

PubMed Central

To obtain more information on the Hevea brasiliensis genome, we sequenced the transcriptome from the vegetative shoot apex yielding 2 311 497 reads. Clustering and assembly of the reads produced a total of 113 313 unique sequences, comprising 28 387 isotigs and 84 926 singletons. Also, 17 819 expressed sequence tag (EST)-simple sequence repeats (SSRs) were identified from the data set. To demonstrate the use of this EST resource for marker development, primers were designed for 430 of the EST-SSRs. Three hundred and twenty-three primer pairs were amplifiable in H. brasiliensis clones. Polymorphic information content values of selected 47 SSRs among 20 H. brasiliensis clones ranged from 0.13 to 0.71, with an average of 0.51. A dendrogram of genetic similarities between the 20 H. brasiliensis clones using these 47 EST-SSRs suggested two distinct groups that correlated well with clone pedigree. These novel EST-SSRs together with the published SSRs were used for the construction of an integrated parental linkage map of H. brasiliensis based on 81 lines of an F1 mapping population. The map consisted of 97 loci, consisting of 37 novel EST-SSRs and 60 published SSRs, distributed on 23 linkage groups and covered 842.9 cM with a mean interval of 11.9 cM and ?4 loci per linkage group. Although the numbers of linkage groups exceed the haploid number (18), but with several common markers between homologous linkage groups with the previous map indicated that the F1 map in this study is appropriate for further study in marker-assisted selection.

Triwitayakorn, Kanokporn; Chatkulkawin, Pornsupa; Kanjanawattanawong, Supanath; Sraphet, Supajit; Yoocha, Thippawan; Sangsrakru, Duangjai; Chanprasert, Juntima; Ngamphiw, Chumpol; Jomchai, Nukoon; Therawattanasuk, Kanikar; Tangphatsornruang, Sithichoke

2011-01-01

249

Genetic structure of the Korean black scraper Thamnaconus modestus inferred from microsatellite marker analysis.  

PubMed

The Korean black scraper, Thamnaconus modestus, is one of the most economically important maricultural fish species in Korea. However, the annual catch of this fish has been continuously declining over the past several decades. In this study, the genetic diversity and relationships among four wild populations and two hatchery stocks of Korean black scraper were assessed based on 16 microsatellite (MS) markers. A total of 319 different alleles were detected over all loci with an average of 19.94 alleles per locus. The hatchery stocks [mean number of alleles (N(A)) = 12, allelic richness (A(R)) = 12, expected heterozygosity (He) = 0.834] showed a slight reduction (P > 0.05) in genetic variability in comparison with wild populations (mean N(A) = 13.86, A(R) = 12.35, He = 0.844), suggesting a sufficient level of genetic variation in the hatchery populations. Similarly low levels of inbreeding and significant Hardy-Weinberg equilibrium deviations were detected in both wild and hatchery populations. The genetic subdivision among all six populations was low but significant (overall F(ST) = 0.008, P < 0.01). Pairwise F(ST), a phylogenetic tree, and multidimensional scaling analysis suggested the existence of three geographically structured populations based on different sea basin origins, although the isolation-by-distance model was rejected. This result was corroborated by an analysis of molecular variance. This genetic differentiation may result from the co-effects of various factors, such as historical dispersal, local environment and ocean currents. These three geographical groups can be considered as independent management units. Our results show that MS markers may be suitable not only for the genetic monitoring of hatchery stocks but also for revealing the population structure of Korean black scraper populations. These results will provide critical information for breeding programs, the management of cultured stocks and the conservation of this species. PMID:23471506

An, Hye Suck; Lee, Jang Wook; Park, Jung Yeon; Jung, Hyung Taek

2013-03-08

250

Construction of a genetic linkage map using simple sequence repeat markers from expressed sequence tags for cassava ( Manihot esculenta Crantz)  

Microsoft Academic Search

Cassava (Manihot esculenta) is an economically important crop that is grown in tropical and sub-tropical regions. Use of molecular technology for genetic\\u000a improvement of cassava has been limited by the lack of a large set of DNA markers and a genetic map. Therefore, the aims here\\u000a were to develop additional simple sequence repeat (SSR) markers from the public expressed sequence

S. Kunkeaw; T. Yoocha; S. Sraphet; A. Boonchanawiwat; O. Boonseng; D. A. Lightfoot; K. Triwitayakorn; S. Tangphatsornruang

2011-01-01

251

Application of microsatellite markers developed for arvicoline species in a population genetic study of the root vole Microtus oeconomus  

Microsoft Academic Search

Using a root vole Microtus oeconomus (Pallas, 1776) population in NE Poland we applied 31 microsatellite markers previously developed for root voles and closely\\u000a related species, with the aim to improve the population genetic tools in this species. Here we present 16 polymorphic microsatellite\\u000a markers grouped into four sets suitable for simultaneous amplification and genetically sex identification in M. oeconomus.

Magdalena Czajkowska; Anetta Borkowska; Monika Wieczorek; Karol Zub

2010-01-01

252

“Refractario” cocoa – genetic identity and genetic structure assessed using microsallite markers  

Technology Transfer Automated Retrieval System (TEKTRAN)

The utilization of germplasm for crop improvement is often hampered by the absence of detailed information regarding the origin, genetic identity and genealogical relationship of germplasm groups or populations. The majority of cacao germplasm held in the Universal Collection of the International Co...

253

Variable Microsatellite Markers for Genotyping Tree Shrews, Tupaia, and their Potential Use in Genetic Studies of Fragmented Populations  

Microsoft Academic Search

We describe the sequences of six primer pairs for the PCR amplification of nuclear microsatellite markers in the tree shrews, Tupaia glis and T. belangeri. Multilocus genotyping based on non-destructive DNA sampling of live-trapped animals reveals high allelic variability (A) and heterozygosity (He) at these loci. Such characteristics make these genetic markers ideal for linkage mapping and comparative genomics, and

Sukamol Srikwan; Kristina Hufford; Lori Eggert; David S Woodruff

2002-01-01

254

RFLP Markers Show Genetic Recombination in Botryotinia fuckeliana (Botrytis cinerea) and Transposable Elements Reveal Two Sympatric Species  

Microsoft Academic Search

Molecular markers revealed that Botryotinia jiickeliana (the teleomorph of Botrytis cinerea), a haploid, filamentous, heterothallic ascomycete, contained a large amount of intrapopulation genetic variation. The markers were used to determine the mode of reproduction and the population structure of this fungus. We did not detect any differentiation between isolates from different organs, collection dates, varieties of grape, or locations in

Tatiana Giraud; Dominique Fortini; Caroline Levis; Pierre Leroux; Yves Brygoo

255

Potential Vulnerability Markers within the Affective Domain in Subjects at Genetic and Clinical High Risk for Schizophrenia  

Microsoft Academic Search

Background: Relative to ample high-risk studies on neurocognitive function, only a few high-risk studies have examined affective functioning components as possible vulnerability markers. In this study, we comprehensively assessed baseline affective functioning in subjects at clinical high risk (CHR) and genetic high risk (GHR) for schizophrenia, and healthy controls (HC), and compared the results to elucidate possible vulnerability markers in

Seung Jae Lee; So Young Yoo; Do-Hyung Kang; Kyung Jin Lee; Tae Hyun Ha; Whee Wee; Ae-Ra Lee; Nam Sick Kim; Jun Soo Kwon

2008-01-01

256

Hierarchical Analysis of Genetic Structure in Native Fire Ant Populations: Results From Three Classes of Molecular Markers  

Microsoft Academic Search

We describe genetic structure at various scales in native populations of the fire ant Solenopsis invicta using two classes of nuclear markers, allozymes and microsatellites, and markers of the mitochondrial genome. Strong structure was found at the nest level in both the monogyne (single queen) and polygyne (multiple queen) social forms using allozymes. Weak but significant microgeographic structure was detected

Kenneth G. Ross; Michael J. B. Krieger; D. DeWayne Shoemaker; Edward L. Vargos; Laurent Kellert

1997-01-01

257

An improved genetic linkage map for cowpea ( Vigna unguiculata L.) Combining AFLP, RFLP, RAPD, biochemical markers, and biological resistance traits  

Microsoft Academic Search

An improved genetic linkage map has been constructed for cowpea (Vigna unguiculata L. Walp.) based on the segregation of various molecular markers and biological resistance traits in a population of 94 recombinant inbred lines (RILs) derived from the cross between 'IT84S-2049' and '524B'. A set of 242 molecular markers, mostly ampli- fied fragment length polymorphism (AFLP), linked to 17 biological

J. T. Ouédraogo; B. S. Gowda; M. Jean; T. J. Close; J. D. Ehlers; A. E. Hall; A. G. Gillaspie; P. A. Roberts; A. M. Ismail; G. Bruening; P. Gepts; M. P. Timko; F. J. Belzile

2002-01-01

258

[Genetic diversity of Beauveria bassiana (Bals.) Vuill. in forest ecosystem assessed by inter-simple sequence repeat (ISSR) markers].  

PubMed

In the present paper, the genetic diversity of 48 Beauveria bassiana strains from different altitudes and at different seasons in Dabie Mountains of western Anhui was estimated using inter-simple sequence repeat (ISSR) markers. Twelve among 33 ISSR primers were chosen for their reproducibility and high polymorphism. Seven (2 - 11) markers per primer were scored, and a total of 84 fragments were amplified, in which 73 (81%) were polymorphic. Genetic diversity analysis revealed a relatively high level of intraspecific genetic diversity of B. bassiana in Dabie Mountains of western Anhui: the percentage of polymorphic loci (PPL) was 81%, Nei's genetic diversity (He) was 0.3187 and Shannon's genetic diversity index (I) was 0.4782. The genetic differentiation, Gst was 0.1028, indicating that a low degree of genetic differentiation occurred in the B. Bassiana among populations. PMID:16941785

Li, Min; Wang, Si-Bao; Fan, Mei-Zhen; Li, Zeng-Zhi; Huang, Yong-Ping

2006-08-01

259

Genetic variability and evolution of the Schistosoma genome analysed by using random amplified polymorphic DNA markers.  

PubMed

The usefulness of random amplified polymorphic DNA markers (RAPD) was assayed in an attempt to discriminate among species, strains and individuals within the genus Schistosoma. Depending on the species, 40-50 arbitrary decamer oligonucleotides were used as primers to amplify total DNA by the polymerase chain reaction (PCR). An important polymorphism was observed among 5 species, allowing a phylogenetic tree to be outlined. These differences can be used for rapid and accurate identification. A limited but easily detectable polymorphism was revealed among 3 strains of a single species (Schistosoma mansoni). Minor differences were observed among individuals of a single strain. A RAPD marker allows sexual discrimination between individuals from the terminal spined-egg species group. Although a limited number of strains have been examined, the results already indicate clearly that RAPD markers constitute a powerful tool for the analysis of genetic variability. This new tool will considerably extend the information available from morphology, isozyme and limited restriction fragment length polymorphism data and opens the way to genetic analysis of these species. PMID:8341320

Barral, V; This, P; Imbert-Establet, D; Combes, C; Delseny, M

1993-06-01

260

Dispersal Capacity and Genetic Structure of Arapaima gigas on Different Geographic Scales Using Microsatellite Markers  

PubMed Central

Despite the ecological and economic importance of the Arapaima gigas (Cuvier 1817), few data about its dispersal capacity are available. The present study was based on the analysis of microsatellite markers in order to estimate the dispersal capacity of the species on fine, meso, and large geographic scales. For this, 561 specimens obtained from stocks separated by distances of up to 25 km (fine scale), 100 km (meso scale), and 1300–2300 km (large scale) were analyzed. The fine scale analysis indicated a marked genetic similarity between lakes, with low genetic differentiation, and significant differences between only a few pairs of sites. Low to moderate genetic differentiation was observed between pairs of sites on a meso scale (100 km), which could be explained by the distances between sites. By contrast, major genetic differentiation was recorded in the large scale analysis, that is, between stocks separated by distances of over 1300 km, with the analysis indicating that differentiation was not related solely to distance. The genetic structuring analysis indicated the presence of two stocks, one represented by the arapaimas of the Mamirauá Reserve, and the other by those of Santarém and Tucuruí. The dispersal of arapaimas over short distances indicates a process of lateral migration within the várzea floodplains, which may be the principal factor determining the considerable homogeneity observed among the várzea lakes. The populations separated by distances of approximately 100 km were characterized by reduced genetic differentiation, which was associated with the geographic distances between sites. Populations separated by distances of over 1300 km were characterized by a high degree of genetic differentiation, which may be related primarily to historical bottlenecks in population size and the sedentary behavior of the species. Evidence was found of asymmetric gene flow, resulting in increasing genetic variability in the population of the Mamirauá Reserve.

Araripe, Juliana; do Rego, Pericles Sena; Queiroz, Helder; Sampaio, Iracilda; Schneider, Horacio

2013-01-01

261

Assessment of Genetic Diversity of Bermudagrass (Cynodon dactylon) Using ISSR Markers.  

PubMed

Bermudagrass (Cynodon spp.) is a major turfgrass for home lawns, public parks, golf courses and sport fields and is known to have originated in the Middle East. Morphological and physiological characteristics are not sufficient to differentiate some bermudagrass genotypes because the differences between them are often subtle and subjected to environmental influences. In this study, twenty seven bermudagrass accessions and introductions, mostly from different parts of Iran, were assayed by inter-simple sequence repeat (ISSR) markers to differentiate and explore their genetic relationships. Fourteen ISSR primers amplified 389 fragments of which 313 (80.5%) were polymorphic. The average polymorphism information content (PIC) was 0.328, which shows that the majority of primers are informative. Cluster analysis using the un-weighted paired group method with arithmetic average (UPGMA) method and Jaccard's similarity coefficient (r = 0.828) grouped the accessions into six main clusters according to some degree to geographical origin, their chromosome number and some morphological characteristics. It can be concluded that there exists a wide genetic base of bermudograss in Iran and that ISSR markers are effective in determining genetic diversity and relationships among them. PMID:22312259

Farsani, Tayebeh Mohammadi; Etemadi, Nematollah; Sayed-Tabatabaei, Badraldin Ebrahim; Talebi, Majid

2011-12-29

262

Genetic diversity of Iranian soft-seed pomegranate genotypes as revealed by fluorescent-AFLP markers.  

PubMed

The amplified fragment length polymorphism (AFLP) technique was used to examine the genetic relationships among 21 Iranian soft-seeded pomegranate (Punica granatum L.) genotypes. Out of 72 fluorescent-AFLP primer combinations screened, 31 were selected to produce the 503 polymorphic markers used in this study. Genetic similarity estimates between genotypes, calculated by the Jaccard's similarity coefficient, ranged from 0.17 to 1.00, while the cophenetic correlation coefficient between the genetic similarities and the unweighted pair group method of arithmetic averages (UPGMA) dendrogram was 0.98. The AFLP-based UPGMA dendrogram revealed two groups within the genotypes at 0.33 similarity coefficient, which reflect fruit traits such as peel and aril color, and seed firmness, as well as region of origin. Our study shows that the use of molecular markers is essential during all steps of germplasm management to avoid genotype redundancy and mislabeling. The present study will be used as a reliable reference to discriminate among these genotypes, to aid management of germplasm collections used to breed new varieties for the Iranian pomegranate industry. PMID:23573023

Sarkhosh, Ali; Zamani, Zabihollah; Fatahi, Reza; Hassani, Mohammad E; Wiedow, Claudia; Buck, Emily; Gardiner, Susan E

2011-06-16

263

Genetic variability of Fusarium wilt pathogen isolates of chickpea (Cicer arietinum L.) assessed by molecular markers.  

PubMed

Genetic variability among 43 isolates of Fusarium oxysporum f.sp. ciceri, the chickpea wilt pathogen, collected from nine states of India including the four well-characterized races of the pathogen were assessed using the molecular markers, RAPDs and AFLP. Principal coordinate analysis of the similarity index data generated from the molecular marker studies mostly gave three different clusters: Of these two clusters represented race-1 and race-2, and the third cluster consisted of race-3 and race-4 pathogen isolates. In RAPDs a fourth cluster was seen which did not go with any of the four races of the pathogen. The molecular markers established the distinctness of race-1 and race-2 pathogen isolates and the close similarity of pathogen isolates of race-3 with that of race-4. AFLP was found to be more informative as it differentiated more number of the pathogen isolates with the known races with minimum of outliers. The high levels of DNA polymorphism observed with the molecular markers suggest the rapid evolution of new recombinants of the pathogen in the chickpea growing fields. PMID:12617504

Sivaramakrishnan, S; Kannan, Seetha; Singh, S D

2002-01-01

264

Assessment of genome origins and genetic diversity in the genus Eleusine with DNA markers.  

PubMed

Finger millet (Eleusine coracana), an allotetraploid cereal, is widely cultivated in the arid and semiarid regions of the world. Three DNA marker techniques, restriction fragment length polymorphism (RFLP), randomly amplified polymorphic DNA (RAPD), and inter simple sequence repeat amplification (ISSR), were employed to analyze 22 accessions belonging to 5 species of Eleusine. An 8 probe--3 enzyme RFLP combination, 18 RAPD primers, and 6 ISSR primers, respectively, revealed 14, 10, and 26% polymorphism in 17 accessions of E. coracana from Africa and Asia. These results indicated a very low level of DNA sequence variability in the finger millets but did allow each line to be distinguished. The different Eleusine species could be easily identified by DNA marker technology and the 16% intraspecific polymorphism exhibited by the two analyzed accessions of E. floccifolia suggested a much higher level of diversity in this species than in E. coracana. Between species, E. coracana and E. indica shared the most markers, while E. indica and E. tristachya shared a considerable number of markers, indicating that these three species form a close genetic assemblage within the Eleusine. Eleusine floccifolia and E. compressa were found to be the most divergent among the species examined. Comparison of RFLP, RAPD, and ISSR technologies, in terms of the quantity and quality of data output, indicated that ISSRs are particularly promising for the analysis of plant genome diversity. PMID:7672607

Salimath, S S; de Oliveira, A C; Godwin, I D; Bennetzen, J L

1995-08-01

265

Genetic Diversity Analysis of Sugarcane Parents in Chinese Breeding Programmes Using gSSR Markers.  

PubMed

Sugarcane is the most important sugar and bioenergy crop in the world. The selection and combination of parents for crossing rely on an understanding of their genetic structures and molecular diversity. In the present study, 115 sugarcane genotypes used for parental crossing were genotyped based on five genomic simple sequence repeat marker (gSSR) loci and 88 polymorphic alleles of loci (100%) as detected by capillary electrophoresis. The values of genetic diversity parameters across the populations indicate that the genetic variation intrapopulation (90.5%) was much larger than that of interpopulation (9.5%). Cluster analysis revealed that there were three groups termed as groups I, II, and III within the 115 genotypes. The genotypes released by each breeding programme showed closer genetic relationships, except the YC series released by Hainan sugarcane breeding station. Using principle component analysis (PCA), the first and second principal components accounted for a cumulative 76% of the total variances, in which 43% were for common parents and 33% were for new parents, respectively. The knowledge obtained in this study should be useful to future breeding programs for increasing genetic diversity of sugarcane varieties and cultivars to meet the demand of sugarcane cultivation for sugar and bioenergy use. PMID:23990759

You, Qian; Xu, Liping; Zheng, Yifeng; Que, Youxiong

2013-08-07

266

Genetic Diversity Analysis of Sugarcane Parents in Chinese Breeding Programmes Using gSSR Markers  

PubMed Central

Sugarcane is the most important sugar and bioenergy crop in the world. The selection and combination of parents for crossing rely on an understanding of their genetic structures and molecular diversity. In the present study, 115 sugarcane genotypes used for parental crossing were genotyped based on five genomic simple sequence repeat marker (gSSR) loci and 88 polymorphic alleles of loci (100%) as detected by capillary electrophoresis. The values of genetic diversity parameters across the populations indicate that the genetic variation intrapopulation (90.5%) was much larger than that of interpopulation (9.5%). Cluster analysis revealed that there were three groups termed as groups I, II, and III within the 115 genotypes. The genotypes released by each breeding programme showed closer genetic relationships, except the YC series released by Hainan sugarcane breeding station. Using principle component analysis (PCA), the first and second principal components accounted for a cumulative 76% of the total variances, in which 43% were for common parents and 33% were for new parents, respectively. The knowledge obtained in this study should be useful to future breeding programs for increasing genetic diversity of sugarcane varieties and cultivars to meet the demand of sugarcane cultivation for sugar and bioenergy use.

You, Qian; Xu, Liping; Zheng, Yifeng; Que, Youxiong

2013-01-01

267

GENETIC ANALYSIS OF FAMILIES WITH AUTOIMMUNE DIABETES AND THYROIDITIS: EVIDENCE FOR COMMON AND UNIQUE GENES  

PubMed Central

Context: Epidemiological data suggest a common genetic susceptibility to Type 1 diabetes (T1D) and autoimmune thyroid disease (AITD). Objective: Our objective was to identify the joint susceptibility genes for T1D and AITD. Design: We conducted a family based linkage and association study. Setting: The study took place at an academic medical center. Participants: Participants included 55 multiplex families (290 individuals) in which T1D and AITD clustered (T1D-AITD families). Main Outcome Measures: We conducted tests for linkage and family-based associations (transmission disequilibrium test) with four candidate genes, human leukocyte antigen (HLA), cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), insulin variable number of tandem repeats (VNTR), and thyroglobulin. Results: Linkage evidence to HLA appeared when subjects with either T1D or AITD were considered affected [maximum LOD score (MLS), 2.2]. The major HLA haplotype contributing to the shared susceptibility was DR3-DQB1*0201, with DR3 conferring most of the shared risk. The CTLA-4 gene showed evidence for linkage only when individuals with both T1D and AITD were considered affected (MLS, 1.7), and the insulin VNTR showed evidence for linkage when individuals with either T1D or AITD were considered affected (MLS, 1.9); i.e. it may contribute to the familial aggregation of T1D and AITD. Conclusions: The HLA class II locus contributes to the shared risk for T1D and AITD, and the major HLA haplotype contributing to this association is DR3-DQB1*0201. Additional non-HLA loci contribute to the joint susceptibility to T1D and AITD, and two potential candidates include the CTLA-4 and insulin VNTR loci.

Golden, Brian; Levin, Lara; Ban, Yoshiyuki; Concepcion, Erlinda; Greenberg, David A.

2005-01-01

268

Genetic linkage maps for Asian and American lotus constructed using novel SSR markers derived from the genome of sequenced cultivar  

PubMed Central

Background The genus Nelumbo Adans. comprises two living species, N. nucifera Gaertan. (Asian lotus) and N. lutea Pers. (American lotus). A genetic linkage map is an essential resource for plant genetic studies and crop improvement but has not been generated for Nelumbo. We aimed to develop genomic simple sequence repeat (SSR) markers from the genome sequence and construct two genetic maps for Nelumbo to assist genome assembly and integration of a genetic map with the genome sequence. Results A total of 86,089 SSR motifs were identified from the genome sequences. Di- and tri-nucleotide repeat motifs were the most abundant, and accounted for 60.73% and 31.66% of all SSRs, respectively. AG/GA repeats constituted 51.17% of dinucleotide repeat motifs, followed by AT/TA (44.29%). Of 500 SSR primers tested, 386 (77.20%) produced scorable alleles with an average of 2.59 per primer, and 185 (37.00%) showed polymorphism among two parental genotypes, N. nucifera ‘Chinese Antique’ and N. lutea ‘AL1’, and six progenies of their F1 population. The normally segregating markers, which comprised 268 newly developed SSRs, 37 previously published SSRs and 53 sequence-related amplified polymorphism markers, were used for genetic map construction. The map for Asian lotus was 365.67 cM with 47 markers distributed in seven linkage groups. The map for American lotus was 524.51 cM, and contained 177 markers distributed in 11 genetic linkage groups. The number of markers per linkage group ranged from three to 34 with an average genetic distance of 3.97 cM between adjacent markers. Moreover, 171 SSR markers contained in linkage groups were anchored to 97 genomic DNA sequence contigs of ‘Chinese Antique’. The 97 contigs were merged into 60 scaffolds. Conclusion Genetic mapping of SSR markers derived from sequenced contigs in Nelumbo enabled the associated contigs to be anchored in the linkage map and facilitated assembly of the genome sequences of ‘Chinese Antique’. The present study reports the first construction of genetic linkage maps for Nelumbo, which can serve as reference linkage maps to accelerate characterization germplasm, genetic mapping for traits of economic interest, and molecular breeding with marker-assisted selection.

2012-01-01

269

Genetic structure and affinities among tribal populations of southern India: a study of 24 autosomal DNA markers  

Microsoft Academic Search

Summary We describe the genetic structure and affinities of five Dravidian-speaking tribal populations inhabiting the Nilgiri hills of Tamil Nadu, in south India, using 24 autosomal DNA markers. Our goals were: (i) to examine what evolutionary forces have most significantly impacted south Indian tribal genetic variation, and (ii) to test whether the phenotypic similarities of some south Indian tribal groups

H. Vishwanathan; E. Deepa; R. Cordaux; M. Stoneking; M. V. Usha Rani; P. P. Majumder

2004-01-01

270

GENETIC MARKER ANALYSIS OF A GLOBAL COLLECTION OF ISOLATES OF CITRUS TRISTEZA VIRUS: CHARACTERIZATION AND DISTRIBUTION OF CTV  

Technology Transfer Automated Retrieval System (TEKTRAN)

Genetic markers amplified by sequence specific primers designed from the partial or complete genome sequences of Citrus tristeza virus (CTV) isolates T3, T30, T36 and VT were used to assess the genetic relatedness of isolates in an international collection of 372 exotic isolates of CTV by comparing...

271

Genetic diversity and structure of farm and genebank accessions of cacao (Theobroma cacao L.) in Cameroon revealed by microsatellite markers  

Technology Transfer Automated Retrieval System (TEKTRAN)

The genetic diversity of 400 accessions collected in cacao farms, 95 genebank and 31 reference accessions was analyzed using 12 microsatelitte markers. The genebank and reference accessions were sub-divided into 12 accession groups (AG) that belong to the traditional cacao genetic groups (GG) Lower ...

272

A DArT marker genetic map of perennial ryegrass (Lolium perenne L.) integrated with detailed comparative mapping information; comparison with existing DArT marker genetic maps of Lolium perenne, L. multiflorum and Festuca pratensis  

PubMed Central

Background Ryegrasses and fescues (genera, Lolium and Festuca) are species of forage and turf grasses which are used widely in agricultural and amenity situations. They are classified within the sub-family Pooideae and so are closely related to Brachypodium distachyon, wheat, barley, rye and oats. Recently, a DArT array has been developed which can be used in generating marker and mapping information for ryegrasses and fescues. This represents a potential common marker set for ryegrass and fescue researchers which can be linked through to comparative genomic information for the grasses. Results A F2 perennial ryegrass genetic map was developed consisting of 7 linkage groups defined by 1316 markers and deriving a total map length of 683 cM. The marker set included 866 DArT and 315 gene sequence-based markers. Comparison with previous DArT mapping studies in perennial and Italian ryegrass (L. multiflorum) identified 87 and 105 DArT markers in common, respectively, of which 94% and 87% mapped to homoeologous linkage groups. A similar comparison with meadow fescue (F. pratensis) identified only 28 DArT markers in common, of which c. 50% mapped to non-homoelogous linkage groups. In L. perenne, the genetic distance spanned by the DArT markers encompassed the majority of the regions that could be described in terms of comparative genomic relationships with rice, Brachypodium distachyon, and Sorghum bicolor. Conclusions DArT markers are likely to be a useful common marker resource for ryegrasses and fescues, though the success in aligning different populations through the mapping of common markers will be influenced by degrees of population interrelatedness. The detailed mapping of DArT and gene-based markers in this study potentially allows comparative relationships to be derived in future mapping populations characterised using solely DArT markers.

2013-01-01

273

HLA-linked genetic markers in Chinese and other Oriental populations.  

PubMed

The polymorphic variants of the HLA-linked genetic markers Bf, C2, C4 and GLO-I were studied in three mongoloid populations. Analysis of linkage dis-equilibrium between these markers and HLA-A, B, C and DR antigens was carried out on test results from 140 unrelated Chinese individuals. The phenotypes BfS and GLO-2 were found at significantly higher frequencies than in Caucasians. BfS was associated with B12 in Japanese but not in Chinese. A single individual with the rare Bf variant S1 was found. No C2 deficient individuals were observed. The C2C (common) allele occurred at a gene frequency of 0.949 and the more basic allele C2B at 0.039. The acidic variant, C2A, was observed at a frequency of 0.011 and appeared to be associated with BfF. Eighty-nine per cent of the Chinese were phenotypically C4FS. In contrast to Bf and C2, each of which is coded for by codominant alleles at a single genetic locus, C4 is coded for by two genes, C4F (Rodgers) and C4S (Chido). The C4F locus allele, C4F1 (extra fast), was strongly associated with HLA-B17, as has been found in other populations, but a new association of the C4S locus deficiency allele, C4so (Ch-), with B17 was also observed. All HLA-B17;C4so haplotypes were BfS position. As has been previously found in Caucasian populations, individuals of the C4F phenotype (i.e. genotypically FsoFso) were all found to be Chido negative. The frequencies of the various HLA-linked genetic markers, however, as much as the frequencies and associations of the HLA antigens themselves, distinguish these populations from other ethnic groups. PMID:6953615

Miniter, P; Chan, K W; Pollack, M S; Dupont, B; O'Neill, G J

1981-11-01

274

Assessment of genetic markers for species differentiation within the Mycobacterium tuberculosis complex.  

PubMed Central

It is important to correctly identify species within the Mycobacterium tuberculosis complex because of the zoonotic implications of bovine tuberculosis, especially in developing countries. We assessed the use of various genetic markers for species-specific identification of mycobacteria from the M. tuberculosis complex. A multiplex PCR designed for detection of the mtp40 and IS1081 elements was optimized and evaluated in 339 mycobacterial strains from different animal and geographic origins. The host range of the IS6110, MPB70, and 16S rRNA genes was also studied by PCR in all the strains. Finally, the usefulness of the genetic markers was compared by an immunoperoxidase test for specific identification of Mycobacterium bovis strains. The mtp40 sequence was detected in 87 of the 91 strains of M. tuberculosis and in 9 of the 11 Mycobacterium africanum strains but not in any of the M. bovis or Mycobacterium microti strains, indicating that the mtp40 element was also found in all of the M. tuberculosis complex strains isolated from seals. This organism is considered to be a true seal pathogen, but its origin is essentially unknown. The finding of the mtp40 element in the strains from seals suggests a closer relationship of these strains with a human origin than to an animal origin. The mtp40 element was not found in any other mycobacterial species included in the study. As a result of this study, we suggest that biochemical tests or alternate genetic markers are still needed to differentiate M. tuberculosis from M. africanum when these species coexist as causative agents of tuberculosis. The immunoperoxidase test worked well for the identification of M. bovis strains. We also report, for the first time, PCR amplification of the repetitive element IS6110 in an isolate of Mycobacterium ulcerans and an isolate of Mycobacterium gilvum, which emphasizes the need for further investigation of the host range of this sequence.

Liebana, E; Aranaz, A; Francis, B; Cousins, D

1996-01-01

275

A comparative survey of genetic diversity among a set of Caricaceae accessions using microsatellite markers.  

PubMed

A preliminary survey of genetic diversity among 34 commercially popular Carica papaya cultivars from India and abroad, 6 accessions of Vasconcellea species and 1 accession of Jacaratia spinosa, was done using 20 simple sequence repeat (SSR) markers. The SSR profiles were used to find out total number of alleles, null and rare alleles, Polymorphism Information Content (PIC) values and to calculate similarity matrix using Jaccard's coefficient. The subsequent dendrogram was made by unweighted pair-group method of arithmetic average (UPGMA) and neighbor-joining method. Based on these parameters a comparison was made between the Indian papaya cultivars and the rest of the accessions. All the markers showed polymorphism and a total of 140 alleles were identified. The average number of alleles was 7 alleles/locus. Categorically the Vasconcellea and Jacaratia species had 54 alleles, the 7 non-Indian Carica papaya accessions had 70 and the 27 Indian accessions had 102 alleles. The average PIC value was 0.735 per marker. A total of 37 rare alleles were identified. Jacaratia spinosa had 17 rare alleles. Nineteen null alleles were detected among the Carica papaya accessions. A Carica papaya accession from South Africa, Hortus Gold had 5 null alleles. The genetic similarity among the accessions ranged from 7% to 67%. In the dendrogram, the Vasconcellea and Jacaratia spinosa accessions separated as a distinct cluster from the rest of the Carica papaya accessions. The study indicated that the accessions of Indian Carica papaya cultivars included in this survey are genetically more diverse than the non-Indian Carica papaya cultivars. PMID:23961410

Sengupta, Samik; Das, Basabdatta; Prasad, Manoj; Acharyya, Pinaki; Ghose, Tapas Kumar

2013-07-26

276

Genetic Markers of IgG Influence the Outcome of Infection with Hepatitis C Virus  

PubMed Central

We examined the role that immunoglobulin GM and KM allotypes—genetic markers of ? and ? chains, respectively—play in the outcome of hepatitis C virus (HCV) infection in white Americans. A total of 119 persons who had cleared HCV and 111 with persistent HCV infection were genotyped for the presence of several GM and KM determinants. Persistent HCV infection was more than three times as likely (odds ratio, 3.50; P = .01) in subjects who were carriers of the GM3 allele than in those who were noncarriers. These results show that particular GM alleles may be important determinants of the outcome of HCV infection.

Pandey, Janardan P.; Namboodiri, Aryan M.; Luo, Yuqun; Wu, Yuping; Elston, Robert C.; Thomas, David L.; Rosen, Hugo R.; Goedert, James J.

2009-01-01

277

Population genetics of the yellow fever mosquito in Trinidad: comparisons of amplified fragment length polymorphism (AFLP) and restriction fragment length polymorphism (RFLP) markers  

Microsoft Academic Search

Recent development of DNA markers provides powerful tools for population genetic analyses. Amplified fragment length polymorphism (AFLP) markers result from a poly- merase chain reaction (PCR)-based DNA fingerprinting technique that can detect multiple restriction fragments in a single polyacrylamide gel, and thus are potentially useful for population genetic studies. Because AFLP markers have to be analysed as dominant loci in

G. Yan; J. Romero-Severson; M. Walton; D. D. CHADEEand; D. W. Severson

1999-01-01

278

Using SSR markers to determine the population genetic structure of wild apricot ( Prunus armeniaca L.) in the Ily Valley of West China  

Microsoft Academic Search

Genetic structure of three wild populations (Xinyuan, Gongliu and Daxigou) of apricot in the Ily Valley, Xinjiang Uygur Autonomous Region of China, was investigated with microsatellite (simple sequence repeat, SSR) markers. The higher polymorphism and greater transportability of these markers between Prunus species proved SSR markers were much efficient for conducting genetic diversity studies in wild apricot. Nei’s gene diversity

He Tian-Ming; Chen Xue-Sen; Xu Zheng; Gao Jiang-Sheng; Lin Pei-Jun; Liu Wen; Liang Qing; Wu Yan

2007-01-01

279

Genetic characterization of 12 heterologous microsatellite markers for the giant tropical tree Cariniana legalis (Lecythidaceae)  

PubMed Central

Twelve microsatellite loci previously developed in the tropical tree Cariniana estrellensis were genetically characterized in Cariniana legalis. Polymorphisms were assessed in 28 C. legalis individuals found between the Pardo and Mogi-Guaçu River basins in the state of São Paulo, Brazil. Of the 12 loci, 10 were polymorphic and exhibited Mendelian inheritance. The allelic richness at each locus ranged from 2-11, with an average of 7 alleles per locus, and the expected heterozygosity ranged from 0.07-0.88. These loci showed a high probability of paternity exclusion. The characteristics of these heterologous microsatellite markers indicate that they are suitable tools for investigating questions concerning population genetics in C. legalis.

2010-01-01

280

Genetic diversity of Tomistoma schlegelii inferred from mtDNA markers.  

PubMed

The genetic diversity of the endangered crocodile Tomistoma schlegelii was characterized using the protein coding ND 6-tRNA(glu)-cyt b and the cytochrome b-control region (cyt b-CR) markers. Concatenate data revealed six haplotypes with an overall haplotype diversity of 0.769 ± 0.039; nucleotide diversity was 0.00535 ± 0.00172. A nearest-neighbor analysis showed that all individuals clustered with four geographic regions (Sumatra, Peninsular Malaysia, Sarawak, and East Kalimantan) and were genetically differentiated. With the exception of the individuals from haplotype H2, which occurred in both Peninsular Malaysia and Sarawak, all other haplotypes were geographically distinct. The H4 lineage, which was found to be the most divergent, clustered exclusively in the basal clade in all phylogenetic trees, and the haplotype network was unconnected at the 95% reconnection limit, suggesting further investigation to establish its possible status as a distinct evolutionary significant unit or a cryptic species. PMID:23325482

Kaur, Taranjeet; Japning, Jeffrine Rovie Ryan; Sabki, Mohamad Shahbudin; Sidik, Irvan; Chong, Lee Kim; Ong, Alan H K

2013-01-17

281

Random amplified polymorphic DNA (RAPD) markers reveal genetic homogeneity in the endangered Himalayan species Meconopsis paniculata and M. simplicifolia  

Microsoft Academic Search

Random amplified polymorphic DNA (RAPD) marker-based analysis was carried out to study the extent of genetic polymorphism between populations of the two endangered Himalayan poppy species, Meconopsis paniculata and M. Simplicifolia. Of the 90 primers tested, 38 revealed marked inter-species genetic polymorphism between individuals of the two species from geographically isolated populations. However, intra-species genetic homogeneity was also evident with

Irshad M. Sulaiman; Seyed E. Hasnain

1996-01-01

282

Genetic Diversity and Linkage Disequilibrium in Chinese Bread Wheat (Triticum aestivum L.) Revealed by SSR Markers  

PubMed Central

Two hundred and fifty bread wheat lines, mainly Chinese mini core accessions, were assayed for polymorphism and linkage disequilibrium (LD) based on 512 whole-genome microsatellite loci representing a mean marker density of 5.1 cM. A total of 6,724 alleles ranging from 1 to 49 per locus were identified in all collections. The mean PIC value was 0.650, ranging from 0 to 0.965. Population structure and principal coordinate analysis revealed that landraces and modern varieties were two relatively independent genetic sub-groups. Landraces had a higher allelic diversity than modern varieties with respect to both genomes and chromosomes in terms of total number of alleles and allelic richness. 3,833 (57.0%) and 2,788 (41.5%) rare alleles with frequencies of <5% were found in the landrace and modern variety gene pools, respectively, indicating greater numbers of rare variants, or likely new alleles, in landraces. Analysis of molecular variance (AMOVA) showed that A genome had the largest genetic differentiation and D genome the lowest. In contrast to genetic diversity, modern varieties displayed a wider average LD decay across the whole genome for locus pairs with r2>0.05 (P<0.001) than the landraces. Mean LD decay distance for the landraces at the whole genome level was <5 cM, while a higher LD decay distance of 5–10 cM in modern varieties. LD decay distances were also somewhat different for each of the 21 chromosomes, being higher for most of the chromosomes in modern varieties (<5?25 cM) compared to landraces (<5?15 cM), presumably indicating the influences of domestication and breeding. This study facilitates predicting the marker density required to effectively associate genotypes with traits in Chinese wheat genetic resources.

Hao, Chenyang; Wang, Lanfen; Ge, Hongmei; Dong, Yuchen; Zhang, Xueyong

2011-01-01

283

Predicting Risk in Space: Genetic Markers for Differential Vulnerability to Sleep Restriction.  

PubMed

Several laboratories have found large, highly reliable individual differences in the magnitude of cognitive performance, fatigue and sleepiness, and sleep homeostatic vulnerability to acute total sleep deprivation and to chronic sleep restriction in healthy adults. Such individual differences in neurobehavioral performance are also observed in space flight as a result of sleep loss. The reasons for these stable phenotypic differential vulnerabilities are unknown: such differences are not yet accounted for by demographic factors, IQ or sleep need, and moreover, psychometric scales do not predict those individuals cognitively vulnerable to sleep loss. The stable, trait-like (phenotypic) inter-individual differences observed in response to sleep loss-with intraclass correlation coefficients accounting for 58%-92% of the variance in neurobehavioral measures- point to an underlying genetic component. To this end, we utilized multi-day highly controlled laboratory studies to investigate the role of various common candidate gene variants-each independently-in relation to cumulative neurobehavioral and sleep homeostatic responses to sleep restriction. These data suggest that common genetic variations (polymorphisms) involved in sleep-wake, circadian, and cognitive regulation may serve as markers for prediction of inter-individual differences in sleep homeostatic and neurobehavioral vulnerability to sleep restriction in healthy adults. Identification of genetic predictors of differential vulnerability to sleep restriction-as determined from candidate gene studies-will help identify astronauts most in need of fatigue countermeasures in space flight and inform medical standards for obtaining adequate sleep in space. This review summarizes individual differences in neurobehavioral vulnerability to sleep deprivation and ongoing genetic efforts to identify markers of such differences. PMID:23524958

Goel, Namni; Dinges, David F

2012-08-01

284

Genetic divergence among Brazilian garlic cultivars based on morphological characters and AFLP markers.  

PubMed

Outside its centers of origin, garlic propagates only asexually. Since asexual reproduction leads to the absence of meiotic recombination, the main garlic cultivars available for cultivation have arisen from the accumulation of somatic mutations in early cultivars. Thus, it is common for a single clone to have different names in different regions. This study aimed to evaluate the genetic diversity of 20 garlic cultivars by using morphological characters and amplified fragment length polymorphism (AFLP) markers to identify possible duplicate cultivars. We assessed 28 morphological characters related to the leaves, bulbs, and bulbils of the garlic plant and divided them into two categories: quantitative and qualitative (14 characters each). For molecular marker-based analysis, we used three AFLP primer combinations. Genetic divergence was calculated using the Jaccard coefficient; the cultivars were grouped using unweighted pair-group mean analysis. The average genetic divergence detected using the morphological characters was 2.30 (range, 0.45-4.70). Plant height and coat adhesion exhibited the highest divergence among the cultivars. The average genetic diversity based on AFLP data was 43% (range, 0-79%). Dendrograms derived from both techniques divided the cultivars into two groups: noble and semi-noble. Together with the divergence within groups, the correlation between morphological and molecular data suggested that the cultivars in the noble group had greater phenotypic stability than those in the semi-noble group. Analysis of Jonas and Quitéria cultivars using these two techniques revealed only slight differences, suggesting that these cultivars may be clones or have a high degree of kinship. PMID:23408414

Morales, R G F; Resende, J T V; Resende, F V; Delatorre, C A; Figueiredo, A S T; Da-Silva, P R

2013-02-04

285

Genetic diversity of Palestine landraces of faba bean (Vicia faba) based on RAPD markers.  

PubMed

Until now, neither phenotypic nor molecular approaches have been used to characterize the landraces of Palestine faba beans (Vicia faba). We used PCR-based RAPD markers to determine the genetic diversity and relatedness among 26 Palestinian faba bean landraces (traditional farmers' varieties) from 8 localities in the West Bank, Palestine. In tests with 37 primers, 14 generated no polymorphic bands, 12 exhibited weak and unclear products, and 11 primers produced good amplification products with high intensity and pattern stability. Ninety-four DNA fragments (loci) were detected, with an average of 8.54 loci per primer and size ranging from 160 to 1370 bp. A minimum of 4 and a maximum of 14 DNA fragments were obtained using (OPA-05 and OPA-09) and (BC-261) primers, respectively. The maximum percentage of polymorphic markers was 71.4 (BC-298) and the minimum was 50.0 (OPA-05, -09, -16). The 11 primers exhibited relatively high collective resolving power (Rp) values of 26.316, and varied from 0.154 for the OPA-09 primer to 5.236 for the BC-261, with an overall mean of 2.392. The primers BC-261, -322, and -298 were found to be the most useful RAPD primers to assess the genetic diversity of Palestinian faba beans, as they revealed relatively high Rp rates (5.236, 3.618, and 3.150, respectively). Based on the Jaccard coefficient, the genetic distance ranged from 0.358 to 0.069, with a mean of 0.213. We conclude that the RAPD technique is useful for determining genetic diversity and for developing suitable fingerprints for faba bean landraces grown in Palestine. PMID:24065673

Basheer-Salimia, R; Shtaya, M; Awad, M; Abdallah, J; Hamdan, Y

2013-09-03

286

Predicting Risk in Space: Genetic Markers for Differential Vulnerability to Sleep Restriction  

PubMed Central

Several laboratories have found large, highly reliable individual differences in the magnitude of cognitive performance, fatigue and sleepiness, and sleep homeostatic vulnerability to acute total sleep deprivation and to chronic sleep restriction in healthy adults. Such individual differences in neurobehavioral performance are also observed in space flight as a result of sleep loss. The reasons for these stable phenotypic differential vulnerabilities are unknown: such differences are not yet accounted for by demographic factors, IQ or sleep need, and moreover, psychometric scales do not predict those individuals cognitively vulnerable to sleep loss. The stable, trait-like (phenotypic) inter-individual differences observed in response to sleep loss—with intraclass correlation coefficients accounting for 58%-92% of the variance in neurobehavioral measures— point to an underlying genetic component. To this end, we utilized multi-day highly controlled laboratory studies to investigate the role of various common candidate gene variants—each independently—in relation to cumulative neurobehavioral and sleep homeostatic responses to sleep restriction. These data suggest that common genetic variations (polymorphisms) involved in sleep-wake, circadian, and cognitive regulation may serve as markers for prediction of inter-individual differences in sleep homeostatic and neurobehavioral vulnerability to sleep restriction in healthy adults. Identification of genetic predictors of differential vulnerability to sleep restriction—as determined from candidate gene studies—will help identify astronauts most in need of fatigue countermeasures in space flight and inform medical standards for obtaining adequate sleep in space. This review summarizes individual differences in neurobehavioral vulnerability to sleep deprivation and ongoing genetic efforts to identify markers of such differences.

Goel, Namni; Dinges, David F.

2013-01-01

287

Genomics and genetics of gonadotropin beta-subunit genes: Unique FSHB and duplicated LHB/CGB loci  

PubMed Central

The follicle stimulating hormone (FSH), luteinizing hormone (LH) and chorionic gonadotropin (HCG) play a critical role in human reproduction. Despite the common evolutionary ancestry and functional relatedness of the gonadotropin hormone beta (GtHB) genes, the single-copy FSHB (at 11p13) and the multi-copy LHB/CGB genes (at 19q13.32) exhibit locus-specific differences regarding their genomic context, evolution, genetic variation and expressional profile. FSHB represents a conservative vertebrate gene with a unique function and it is located in a structurally stable gene-poor region. In contrast, the primate-specific LHB/CGB gene cluster is located in a gene-rich genomic context and demonstrates an example of evolutionary young and unstable genomic region. The gene cluster is shaped by a constant balance between selection that acts on specific functions of the loci and frequent gene conversion events among duplicons. As the transcription of the GtHB genes is rate-limiting in the assembly of respective hormones, the genomic and genetic context of the FSHB and the LHB/CGB genes largely affects the profile of the hormone production.

Nagirnaja, Liina; Rull, Kristiina; Uuskula, Liis; Hallast, Pille; Grigorova, Marina; Laan, Maris

2010-01-01

288

Genetic markers substantiate long-term storage and utilization of sperm by female painted turtles.  

PubMed

Most studies of genetic parentage in natural populations have been limited to a single breeding season or reproductive episode and, thus, provide only a snapshot of individuals' mating behaviours. Female turtles can store viable sperm in their reproductive tracts for as long as several years, but the extent to which this capacity is utilized in nature has remained unknown. Here, we employ microsatellite markers to assess genetic paternity in successive clutches of individually marked, free-ranging female painted turtles (Chrysemys picta) over a four year period. The genetic data from 113 clutches from this natural population demonstrate that most females (80.5%) remated each year and that each female generally used a single male's sperm to fertilize all clutches laid within a year. However, sperm usage among females varied considerably, and some females apparently used sperm that had been stored for up to three years to fertilize some or all eggs laid in consecutive nesting seasons. Thus, remating by females is not necessary for continued offspring production from a given sire. Furthermore, 13.2% of all clutches examined showed evidence of multiple paternity, and the genetic paternity patterns across years suggest a 'last in, first out' operation of the females' sperm storage tubules. PMID:11488975

Pearse, D E; Janzen, F J; Avise, J C

2001-03-01

289

Study Of Genetic Diversity Between Grasspea Landraces Using Morphological And Molecular Marker  

NASA Astrophysics Data System (ADS)

Grass pea is a beneficial crop to Iran since it has some major advantageous such as high grain and forage quality, high drought tolerance and medium level of salinity tolerance and a good native germplasm variation which accessible for breeding programs. This study was carried out to evaluate morphological traits of the grass pea landraces using a randomized complete block design with 3 replications at Research Farm of Isfahan University of Technology. To evaluate genetic diversity of 14 grass pea landraces from various locations in Iran were investigated using 32 RAPD & ISJ primers at Biocenter of University of Zabol. Analysis of variance indicated a highly significant differences among 14 grass pea landrace for the morphological traits. Average of polymorphism percentage of RAPD primer was 73.9%. Among used primer, 12 random primers showed polymorphism and a total of 56 different bands were observed in the genotypes. Jafar-abad and Sar-chahan genotypes with similarity coefficient of 66% and Khoram-abad 2 and Khoram-abad 7 genotypes with similarity coefficient of 3% were the most related and the most distinct genotypes, respectively. Fourteen primers out of 17 semi random primers produced 70 polymorphic bands which included 56% of the total 126 produced bands. Genetic relatedness among population was investigated using Jacard coefficient and unweighted pair group mean analysis (UPGMA) algorithm. The result of this research verified possibility of use of RAPD & ISJ markers for estimation of genetic diversity, management of genetic resources and determination of repetitive accessions in grass pea.

Sedehi, Abbasali Vahabi; Lotfi, Asefeh; Solooki, Mahmood

2008-01-01

290

Association of Genetic Markers with CSF Oligoclonal Bands in Multiple Sclerosis Patients  

PubMed Central

Objective to explore the association between genetic markers and Oligoclonal Bands (OCB) in the Cerebro Spinal Fluid (CSF) of Italian Multiple Sclerosis patients. Methods We genotyped 1115 Italian patients for HLA-DRB1*15 and HLA-A*02. In a subset of 925 patients we tested association with 52 non-HLA SNPs associated with MS susceptibility and we calculated a weighted Genetic Risk Score. Finally, we performed a Genome Wide Association Study (GWAS) with OCB status on a subset of 562 patients. The best associated SNPs of the Italian GWAS were replicated in silico in Scandinavian and Belgian populations, and meta-analyzed. Results HLA-DRB1*15 is associated with OCB+: p?=?0.03, Odds Ratio (OR)?=?1.6, 95% Confidence Limits (CL)?=?1.1–2.4. None of the 52 non-HLA MS susceptibility loci was associated with OCB, except one SNP (rs2546890) near IL12B gene (OR: 1.45; 1.09–1.92). The weighted Genetic Risk Score mean was significantly (p?=?0.0008) higher in OCB+ (7.668) than in OCB? (7.412) patients. After meta-analysis on the three datasets (Italian, Scandinavian and Belgian) for the best associated signals resulted from the Italian GWAS, the strongest signal was a SNP (rs9320598) on chromosome 6q (p?=?9.4×10?7) outside the HLA region (65 Mb). Discussion genetic factors predispose to the development of OCB.

Esposito, Federica; Lucenti, Ausiliatrice; Harbo, Hanne F.; Goris, An; Kockum, Ingrid; Oturai, Annette Bang; Celius, Elisabeth Gulowsen; Mero, Inger L.; Dubois, Benedicte; Olsson, Tomas; S?ndergaard, Helle Bach; Cusi, Daniele; Lupoli, Sara; Andreassen, Bettina Kulle; Myhr, Kjell-Morten; Guerini, Franca R.; Comi, Giancarlo

2013-01-01

291

Population genetics of Sargassum horneri (Fucales, Phaeophyta) in China revealed by ISSR and SRAP markers  

NASA Astrophysics Data System (ADS)

Sargassum horneri is a common brown macro-alga that is found in the inter-tidal ecosystems of China. To investigate the current status of seaweed resources and provide basic data for its sustainable development, ISSR (inter simple sequence repeat) and SRAP (sequence related amplified polymorphism) markers were used to analyze the population genetics among nine natural populations of S. horneri. The nine studied populations were distributed over 2 000 km from northeast to south China. The percentage of polymorphic loci P % (ISSR, 99.44%; SRAP, 100.00%), Nei's genetic diversity H (ISSR, 0.107-0.199; SRAP, 0.100-0.153), and Shannon's information index I (ISSR, 0.157-0.291; SRAP, 0.148-0.219) indicated a fair amount of genetic variability among the nine populations. Moreover, the high degree of gene differentiation G st (ISSR, 0.654; SRAP, 0.718) and low gene flow N m (ISSR, 0.265; SRAP, 0.196) implied that there was significant among-population differentiation, possibly as a result of habitat fragmentation. The matrices of genetic distances and fixation indices ( F st) among the populations correlated well with their geographical distribution (Mantel test R =0.541 5, 0.541 8; P =0.005 0, 0.002 0 and R =0.728 6, 0.641 2; P =0.001 0, 0.001 0, respectively); the Rongcheng population in the Shandong peninsula was the only exception. Overall, the genetic differentiation agreed with the geographic isolation. The fair amount of genetic diversity that was revealed in the S. horneri populations in China indicated that the seaweed resources had not been seriously affected by external factors.

Yu, Shenhui; Chong, Zhuo; Zhao, Fengjuan; Yao, Jianting; Duan, Delin

2013-05-01

292

Linkage Analysis of Quantitative Traits in an Interspecific Cross of Tomato (Lycopersicon esculentum X Lycopersicon pimpinell~olium) by Means of Genetic Markers  

Microsoft Academic Search

Linkage relationships between loci affecting quantitative traits (QTL) and marker loci were examined in an interspecific cross between Lycopersicon esculentum and Lycopersicon pimpinellifolium. Parental lines differed for six morphological markers and for four electrophoretic markers. Almost 1700 F-2 plants were scored with respect to the genetic markers and also with respect to 18 quantitative traits. Major genes affecting the quantitative

J. I. Weller; M. Soller; T. Brody

1988-01-01

293

Genetic structure and ecogeographical adaptation in wild barley (Hordeum chilense Roemer et Schultes) as revealed by microsatellite markers  

PubMed Central

Background Multi-allelic microsatellite markers have become the markers of choice for the determination of genetic structure in plants. Synteny across cereals has allowed the cross-species and cross-genera transferability of SSR markers, which constitute a valuable and cost-effective tool for the genetic analysis and marker-assisted introgression of wild related species. Hordeum chilense is one of the wild relatives with a high potential for cereal breeding, due to its high crossability (both interspecies and intergenera) and polymorphism for adaptation traits. In order to analyze the genetic structure and ecogeographical adaptation of this wild species, it is necessary to increase the number of polymorphic markers currently available for the species. In this work, the possibility of using syntenic wheat SSRs as a new source of markers for this purpose has been explored. Results From the 98 wheat EST-SSR markers tested for transferability and polymorphism in the wild barley genome, 53 primer pairs (54.0%) gave cross-species transferability and 20 primer pairs (20.4%) showed polymorphism. The latter were used for further analysis in the H. chilense germplasm. The H. chilense-Triticum aestivum addition lines were used to test the chromosomal location of the new polymorphic microsatellite markers. The genetic structure and diversity was investigated in a collection of 94 H. chilense accessions, using a set of 49 SSR markers distributed across the seven chromosomes. Microsatellite markers showed a total of 351 alleles over all loci. The number of alleles per locus ranged from two to 27, with a mean of 7.2 alleles per locus and a mean Polymorphic Information Content (PIC) of 0.5. Conclusions According to the results, the germplasm can be divided into two groups, with morphological and ecophysiological characteristics being key determinants of the population structure. Geographic and ecological structuring was also revealed in the analyzed germplasm. A significant correlation between geographical and genetic distance was detected in the Central Chilean region for the first time in the species. In addition, significant ecological influence in genetic distance has been detected for one of the population structure groups (group II) in the Central Chilean region. Finally, the association of the SSR markers with ecogeographical variables was investigated and one marker was found significantly associated with precipitation. These findings have a potential application in cereal breeding.

2010-01-01

294

Characterization of a New Vaccinia virus Isolate Reveals the C23L Gene as a Putative Genetic Marker for Autochthonous Group 1 Brazilian Vaccinia virus  

PubMed Central

Since 1999, several Vaccinia virus (VACV) isolates, the etiological agents of bovine vaccinia (BV), have been frequently isolated and characterized with various biological and molecular methods. The results from these approaches have grouped these VACV isolates into two different clusters. This dichotomy has elicited debates surrounding the origin of the Brazilian VACV and its epidemiological significance. To ascertain vital information to settle these debates, we and other research groups have made efforts to identify molecular markers to discriminate VACV from other viruses of the genus Orthopoxvirus (OPV) and other VACV-BR groups. In this way, some genes have been identified as useful markers to discriminate between the VACV-BR groups. However, new markers are needed to infer ancestry and to correlate each sample or group with its unique epidemiological and biological features. The aims of this work were to characterize a new VACV isolate (VACV DMTV-2005) molecularly and biologically using conserved and non-conserved gene analyses for phylogenetic inference and to search for new genes that would elucidate the VACV-BR dichotomy. The VACV DMTV-2005 isolate reported in this study is biologically and phylogenetically clustered with other strains of Group 1 VACV-BR, the most prevalent VACV group that was isolated during the bovine vaccinia outbreaks in Brazil. Sequence analysis of C23L, the gene that encodes for the CC-chemokine-binding protein, revealed a ten-nucleotide deletion, which is a new Group 1 Brazilian VACV genetic marker. This deletion in the C23L open reading frame produces a premature stop-codon that is shared by all Group 1 VACV-BR strains and may also reflect the VACV-BR dichotomy; the deletion can also be considered to be a putative genetic marker for non-virulent Brazilian VACV isolates and may be used for the detection and molecular characterization of new isolates.

Oliveira, Danilo B.; Franco-Luiz, Ana P. M.; Campos, Rafael K.; Guedes, Maria I. M.; Fonseca, Flavio G.; Trindade, Giliane S.; Drumond, Betania P.; Kroon, Erna G.; Abrahao, Jonatas S.

2012-01-01

295

Distribution of genetic markers of fecal pollution on a freshwater sandy shoreline in proximity to wastewater effluent.  

PubMed

Water, sand, and sediment from a Lake Superior harbor site continuously receiving wastewater effluent was sampled monthly for June to October 2010 and from May to September 2011. Understanding the dynamics of genetic markers of fecal bacteria in these matrices is essential to accurately characterizing health risks. Genetic markers for enterococci, total Bacteroides, and human-associated Bacteroides were measured in site-water, sand, and sediment and in final effluent by quantitative PCR. The similarity between the quantity of molecular markers in the water column and effluent indicated that the abundance of genetic markers in the water column was likely controlled by effluent inputs. Effluent turbidity was positively correlated (p ? 0.05) with AllBac and HF183 in final effluent and AllBac in the water column. In sand and sediment, Entero1 and AllBac were most abundant in the upper 1-3 cm depths, whereas HF183 was most abundant in the upper 1 cm of sand and at 7 cm in sediment. The AllBac and Entero1 markers were 1- and 2-orders of magnitude more abundant in sand and sediment relative to the water column per unit mass. These results indicate that sand and sediment may act as reservoirs for genetic markers of fecal pollution at some freshwater sites. PMID:23473470

Eichmiller, Jessica J; Hicks, Randall E; Sadowsky, Michael J

2013-03-21

296

Genetic Diversity and Relatedness of Sweet Cherry (Prunus Avium L.) Cultivars Based on Single Nucleotide Polymorphic Markers  

PubMed Central

Most previous studies on genetic fingerprinting and cultivar relatedness in sweet cherry were based on isoenzyme, RAPD, and simple sequence repeat (SSR) markers. This study was carried out to assess the utility of single nucleotide polymorphism (SNP) markers generated from 3? untranslated regions (UTR) for genetic fingerprinting in sweet cherry. A total of 114 sweet cherry germplasm representing advanced selections, commercial cultivars, and old cultivars imported from different parts of the world were screened with seven SSR markers developed from other Prunus species and with 40 SNPs obtained from 3? UTR sequences of Rainier and Bing sweet cherry cultivars. Both types of marker study had 99 accessions in common. The SSR data was used to validate the SNP results. Results showed that the average number of alleles per locus, mean observed heterozygosity, expected heterozygosity, and polymorphic information content values were higher in SSRs than in SNPs although both set of markers were similar in their grouping of the sweet cherry accessions as shown in the dendrogram. SNPs were able to distinguish sport mutants from their wild type germplasm. For example, “Stella” was separated from “Compact Stella.” This demonstrates the greater power of SNPs for discriminating mutants from their original parents than SSRs. In addition, SNP markers confirmed parentage and also determined relationships of the accessions in a manner consistent with their pedigree relationships. We would recommend the use of 3? UTR SNPs for genetic fingerprinting, parentage verification, gene mapping, and study of genetic diversity in sweet cherry.

Fernandez i Marti, Angel; Athanson, Blessing; Koepke, Tyson; Font i Forcada, Carolina; Dhingra, Amit; Oraguzie, Nnadozie

2012-01-01

297

Genetic diversity and relatedness of sweet cherry (prunus avium L.) cultivars based on single nucleotide polymorphic markers.  

PubMed

Most previous studies on genetic fingerprinting and cultivar relatedness in sweet cherry were based on isoenzyme, RAPD, and simple sequence repeat (SSR) markers. This study was carried out to assess the utility of single nucleotide polymorphism (SNP) markers generated from 3' untranslated regions (UTR) for genetic fingerprinting in sweet cherry. A total of 114 sweet cherry germplasm representing advanced selections, commercial cultivars, and old cultivars imported from different parts of the world were screened with seven SSR markers developed from other Prunus species and with 40 SNPs obtained from 3' UTR sequences of Rainier and Bing sweet cherry cultivars. Both types of marker study had 99 accessions in common. The SSR data was used to validate the SNP results. Results showed that the average number of alleles per locus, mean observed heterozygosity, expected heterozygosity, and polymorphic information content values were higher in SSRs than in SNPs although both set of markers were similar in their grouping of the sweet cherry accessions as shown in the dendrogram. SNPs were able to distinguish sport mutants from their wild type germplasm. For example, "Stella" was separated from "Compact Stella." This demonstrates the greater power of SNPs for discriminating mutants from their original parents than SSRs. In addition, SNP markers confirmed parentage and also determined relationships of the accessions in a manner consistent with their pedigree relationships. We would recommend the use of 3' UTR SNPs for genetic fingerprinting, parentage verification, gene mapping, and study of genetic diversity in sweet cherry. PMID:22737155

Fernandez I Marti, Angel; Athanson, Blessing; Koepke, Tyson; Font I Forcada, Carolina; Dhingra, Amit; Oraguzie, Nnadozie

2012-06-25

298

Comparison of anonymous and targeted molecular markers for the estimation of genetic diversity in ex situ conserved Lactuca.  

PubMed

The anonymous marker systems microsatellites (simple sequence repeats), amplified fragment length polymorphisms and sequence-specific amplified polymorphisms were compared with the targeted marker systems sequence-related amplified polymorphisms, target region amplification polymorphisms and nucleotide binding site profiling for their ability to describe the genetic diversity in a selected set of 80 Lactuca accessions. The accessions were also described morphologically, and all characterisation methods were evaluated against the genetic diversity assessed by a panel of three crop experts. The morphological data showed a low level of association with the molecular data, and did not display a consistently better relationship with the experts' assessments in comparison with the molecular data. In general, the diversity described by the targeted molecular markers did not differ markedly from that of the anonymous markers, resulting in only slight differences in performance when related to the expert-based assessments. It was argued that markers targeted to specific gene sequences may still behave as anonymous markers and that the type of marker system used is irrelevant when at low taxonomic levels a clear genetic structure is absent due to intensive breeding activities. PMID:19697006

van Treuren, R; van Hintum, Th J L

2009-08-21

299

Genetic Grouping of Medulloblastomas by Representative Markers in Pathologic Diagnosis1  

PubMed Central

A recent analysis of the genetic features of medulloblastoma (MB) suggested classification into distinct subgroups according to gene expression profiles, including the Wingless signaling pathway-activated group (WNT group), the Sonic Hedgehog signaling pathway-activated group (SHH group), group 3, and group 4. To classify MB according to genetic features in practice, we analyzed 74 MBs using representative markers of each group. Based on immunohistochemistries (IHC), cytogenetic alterations, and a CTNNB1 mutation study, the patients were divided into the following three groups: cases showing nuclear ?-catenin and/or CTNNB1 mutation and/or monosomy 6 were included in the WNT group (14/74, 18.9%); cases expressing GAB1 were included in the SHH group (15/74, 20.2%); cases that did not show positivity for markers of the WNT or SHH group were included in the non-WNT/SHH group (45/74, 60.6%). Immunoexpression of NPR3 seemed to lack sensitivity for classifying group 3, showing diffuse positivity in only two cases. KCNA1 was not specific to group 4 because it was expressed in all groups. Cases in the WNT group showed a slightly better survival than those in the SHH or non-WNT/SHH group, although additional cases are required for statistical significance. Isochromosome 17q (P = .002) and the large cell/anaplastic variant (P = .002) were demonstrated to be poor prognostic indicators in multivariate analysis. The representative IHC and cytogenetic data facilitated the division of MBs into the WNT and SHH groups; however, more specific markers should be added for the identification of group 3 and group 4 in practice.

Min, Hye Sook; Lee, Ji Yeoun; Kim, Seung-Ki; Park, Sung-Hye

2013-01-01

300

Estimating additive and non-additive genetic variances and predicting genetic merits using genome-wide dense single nucleotide polymorphism markers.  

PubMed

Non-additive genetic variation is usually ignored when genome-wide markers are used to study the genetic architecture and genomic prediction of complex traits in human, wild life, model organisms or farm animals. However, non-additive genetic effects may have an important contribution to total genetic variation of complex traits. This study presented a genomic BLUP model including additive and non-additive genetic effects, in which additive and non-additive genetic relation matrices were constructed from information of genome-wide dense single nucleotide polymorphism (SNP) markers. In addition, this study for the first time proposed a method to construct dominance relationship matrix using SNP markers and demonstrated it in detail. The proposed model was implemented to investigate the amounts of additive genetic, dominance and epistatic variations, and assessed the accuracy and unbiasedness of genomic predictions for daily gain in pigs. In the analysis of daily gain, four linear models were used: 1) a simple additive genetic model (MA), 2) a model including both additive and additive by additive epistatic genetic effects (MAE), 3) a model including both additive and dominance genetic effects (MAD), and 4) a full model including all three genetic components (MAED). Estimates of narrow-sense heritability were 0.397, 0.373, 0.379 and 0.357 for models MA, MAE, MAD and MAED, respectively. Estimated dominance variance and additive by additive epistatic variance accounted for 5.6% and 9.5% of the total phenotypic variance, respectively. Based on model MAED, the estimate of broad-sense heritability was 0.506. Reliabilities of genomic predicted breeding values for the animals without performance records were 28.5%, 28.8%, 29.2% and 29.5% for models MA, MAE, MAD and MAED, respectively. In addition, models including non-additive genetic effects improved unbiasedness of genomic predictions. PMID:23028912

Su, Guosheng; Christensen, Ole F; Ostersen, Tage; Henryon, Mark; Lund, Mogens S

2012-09-13

301

Estimating Additive and Non-Additive Genetic Variances and Predicting Genetic Merits Using Genome-Wide Dense Single Nucleotide Polymorphism Markers  

PubMed Central

Non-additive genetic variation is usually ignored when genome-wide markers are used to study the genetic architecture and genomic prediction of complex traits in human, wild life, model organisms or farm animals. However, non-additive genetic effects may have an important contribution to total genetic variation of complex traits. This study presented a genomic BLUP model including additive and non-additive genetic effects, in which additive and non-additive genetic relation matrices were constructed from information of genome-wide dense single nucleotide polymorphism (SNP) markers. In addition, this study for the first time proposed a method to construct dominance relationship matrix using SNP markers and demonstrated it in detail. The proposed model was implemented to investigate the amounts of additive genetic, dominance and epistatic variations, and assessed the accuracy and unbiasedness of genomic predictions for daily gain in pigs. In the analysis of daily gain, four linear models were used: 1) a simple additive genetic model (MA), 2) a model including both additive and additive by additive epistatic genetic effects (MAE), 3) a model including both additive and dominance genetic effects (MAD), and 4) a full model including all three genetic components (MAED). Estimates of narrow-sense heritability were 0.397, 0.373, 0.379 and 0.357 for models MA, MAE, MAD and MAED, respectively. Estimated dominance variance and additive by additive epistatic variance accounted for 5.6% and 9.5% of the total phenotypic variance, respectively. Based on model MAED, the estimate of broad-sense heritability was 0.506. Reliabilities of genomic predicted breeding values for the animals without performance records were 28.5%, 28.8%, 29.2% and 29.5% for models MA, MAE, MAD and MAED, respectively. In addition, models including non-additive genetic effects improved unbiasedness of genomic predictions.

Su, Guosheng; Christensen, Ole F.; Ostersen, Tage; Henryon, Mark; Lund, Mogens S.

2012-01-01

302

Inter and intra subpopulation genetic variability of roe deer (Capreolus capreolus L.) assessed by I and II class genetic markers.  

PubMed

The material was collected in three regions of Poland and consisted of 105 randomly chosen individuals killed during hunts (49 males, 56 females), out of which 51 were from Wielkopolska, 22 from Podkarpacie and 32 from Warmia. From each animal a blood sample was taken from the chest, stored in a probe with K2EDTA and frozen. The serum was used to establish the genotype for transferin and albumin whereas the samples with erythrocytes provided information on hemoglobin genotype. DNA was isolated from samples from each individual. Characteristics of eight (from among twelve studied) microsatellite loci and genetic distances were estimated by the use of standard computer package programs. Generally, monomorphism in blood proteins was registered. For the microsatellite loci the number of alleles ranged from 3 in the RT27-6-Fa locus (effectively two as the third allele was present only in two subpopulations with a very low frequency) to 10 in RT1-VI. Five loci showed heterozygosity of 0.5 or above which suggests their usefulness in parentage control. Considerable genetic distances (corresponding to geographical mileages) between the subpopulations were observed based on microsatellite markers. PMID:22195465

Kamieniarz, Robert; Wolc, Anna; Lisowski, Miros?aw; Dabert, Miros?awa; Grajewski, Bartosz; Steppa, Ryszard; Szwaczkowski, Tomasz

2011-01-01

303

A High Density Consensus Genetic Map of Tetraploid Cotton That Integrates Multiple Component Maps through Molecular Marker Redundancy Check  

PubMed Central

A consensus genetic map of tetraploid cotton was constructed using six high-density maps and after the integration of a sequence-based marker redundancy check. Public cotton SSR libraries (17,343 markers) were curated for sequence redundancy using 90% as a similarity cutoff. As a result, 20% of the markers (3,410) could be considered as redundant with some other markers. The marker redundancy information had been a crucial part of the map integration process, in which the six most informative interspecific Gossypium hirsutum×G. barbadense genetic maps were used for assembling a high density consensus (HDC) map for tetraploid cotton. With redundant markers being removed, the HDC map could be constructed thanks to the sufficient number of collinear non-redundant markers in common between the component maps. The HDC map consists of 8,254 loci, originating from 6,669 markers, and spans 4,070 cM, with an average of 2 loci per cM. The HDC map presents a high rate of locus duplications, as 1,292 markers among the 6,669 were mapped in more than one locus. Two thirds of the duplications are bridging homoeologous AT and DT chromosomes constitutive of allopolyploid cotton genome, with an average of 64 duplications per AT/DT chromosome pair. Sequences of 4,744 mapped markers were used for a mutual blast alignment (BBMH) with the 13 major scaffolds of the recently released Gossypium raimondii genome indicating high level of homology between the diploid D genome and the tetraploid cotton genetic map, with only a few minor possible structural rearrangements. Overall, the HDC map will serve as a valuable resource for trait QTL comparative mapping, map-based cloning of important genes, and better understanding of the genome structure and evolution of tetraploid cotton.

Blenda, Anna; Fang, David D.; Rami, Jean-Francois; Garsmeur, Olivier; Luo, Feng; Lacape, Jean-Marc

2012-01-01

304

Development of microsatellite markers to genetically differentiate populations of Octopus minor from Korea and China.  

PubMed

Of the more than 300 octopus species, Octopus minor is one of the most popular and economically important species in Eastern Asia, including Korea, along with O. vulgaris, O. ocellatus, and O. aegina. We developed 19 microsatellite markers from Octopus minor and eight polymorphic markers were developed to analyze the genetic diversity and relationships among four octopus populations from Korea and three from China. The number of alleles per locus varied from 10 to 49, and allelic richness per locus ranged from 2 to 16.4 across all populations. The average allele number among the populations was 11.1, with a minimum of 8.3 and a maximum of 13.6. The mean allelic richness was 8.7 in all populations. The Hardy-Weinberg equilibrium (HWE) test revealed significant deviation in 19 of the 56 single-locus sites, and null alleles were presumed in five of eight loci. The pairwise F ( ST ) values between populations from Korea and China differed significantly in all pairwise comparisons. The genetic distances between the China and Korea samples ranged from 0.161 to 0.454. The genetic distances among the populations from Korea ranged from 0.033 to 0.090, with an average of 0.062; those among populations from China ranged from 0.191 to 0.316, with an average of 0.254. The populations from Korea and China formed clearly separated into clusters via an unweighted pair group method with arithmetic mean dendrogram. Furthermore, a population from muddy flats on the western coast of the Korean Peninsula and one from a rocky area on Jeju Island formed clearly separated subclusters. An assignment test based on the allele distribution discriminated between the Korean and Chinese origins with 96.9 % accuracy. PMID:22707143

Kang, Jung-Ha; Kim, Yi-Kyung; Park, Jung-Youn; An, Chel-Min; Jun, Je-Chun

2012-06-16

305

Genetic diversity and identification of Chinese-grown pecan using ISSR and SSR markers.  

PubMed

Pecan is an important horticultural nut crop originally from North America and now widely cultivated in China for its high ecological, ornamental and economic value. Currently, there are over one hundred cultivars grown in China, including introduced American cultivars and Chinese seedling breeding cultivars. Molecular markers were used to assess the genetic diversity of these cultivars and to identify the pedigrees of fine pecan plants with good characteristics and no cultivar-related data. A total of 77 samples grown in China were studied, including 14 introduced cultivars, 12 domestic seedling breeding cultivars, and 49 fine pecan plants with no cultivar data, together with Carya cathayensis and Juglans nigra. A total of 77 ISSR and 19 SSR primers were prescreened; 10 ISSR and eight SSR primers were selected, yielding a total of 94 amplified bands (100% polymorphic) in the range of 140-1,950 bp for the ISSR and 70 amplified bands (100% polymorphic) in the range of 50-350 bp for SSR markers. Genetic diversity analyses indicated Chinese-grown pecan cultivars and fine plants had significant diversity at the DNA level. The dengrograms constructed with ISSR, SSR or combined data were very similar, but showed very weak grouping association with morphological characters. However, the progeny were always grouped with the parents. The great diversity found among the Chinese cultivars and the interesting germplasm of the fine pecan plants analyzed in this study are very useful for increasing the diversity of the pecan gene pool. All 77 accessions in this study could be separated based on the ISSR and SSR fingerprints produced by one or more primers. The results of our study also showed that ISSR and SSR techniques were both suitable for genetic diversity analyses and the identification of pecan resources. PMID:22146370

Jia, Xiao-Dong; Wang, Tao; Zhai, Min; Li, Yong-Rong; Guo, Zhong-Ren

2011-12-06

306

Detection of segregation distortion loci in triticale (x Triticosecale Wittmack) based on a high-density DArT marker consensus genetic linkage map  

PubMed Central

Background Triticale is adapted to a wide range of abiotic stress conditions, is an important high-quality feed stock and produces similar grain yield but more biomass compared to other crops. Modern genomic approaches aimed at enhancing breeding progress in cereals require high-quality genetic linkage maps. Consensus maps are genetic maps that are created by a joint analysis of the data from several segregating populations and different approaches are available for their construction. The phenomenon that alleles at a locus deviate from the Mendelian expectation has been defined as segregation distortion. The study of segregation distortion is of particular interest in doubled haploid (DH) populations due to the selection pressure exerted on the plants during the process of their establishment. Results The final consensus map, constructed out of six segregating populations derived from nine parental lines, incorporated 2555 DArT markers mapped to 2602 loci (1929 unique). The map spanned 2309.9 cM with an average number of 123.9 loci per chromosome and an average marker density of one unique locus every 1.2 cM. The R genome showed the highest marker coverage followed by the B genome and the A genome. In general, locus order was well maintained between the consensus linkage map and the component maps. However, we observed several groups of loci for which the colinearity was slightly uneven. Among the 2602 loci mapped on the consensus map, 886 showed distorted segregation in at least one of the individual mapping populations. In several DH populations derived by androgenesis, we found chromosomes (2B, 3B, 1R, 2R, 4R and 7R) containing regions where markers exhibited a distorted segregation pattern. In addition, we observed evidence for segregation distortion between pairs of loci caused either by a predominance of parental or recombinant genotypes. Conclusions We have constructed a reliable, high-density DArT marker consensus genetic linkage map as a basis for genomic approaches in triticale research and breeding, for example for multiple-line cross QTL mapping experiments. The results of our study exemplify the tremendous impact of different DH production techniques on allele frequencies and segregation distortion covering whole chromosomes.

2011-01-01

307

DNA-Based Genetic Markers for Rapid Cycling Brassica Rapa (Fast Plants Type) Designed for the Teaching Laboratory  

PubMed Central

We have developed DNA-based genetic markers for rapid cycling Brassica rapa (RCBr), also known as Fast Plants. Although markers for B. rapa already exist, ours were intentionally designed for use in a teaching laboratory environment. The qualities we selected for were robust amplification in PCR, polymorphism in RCBr strains, and alleles that can be easily resolved in simple agarose slab gels. We have developed two single nucleotide polymorphism (SNP) based markers and 14 variable number tandem repeat (VNTR)-type markers spread over four chromosomes. The DNA sequences of these markers represent variation in a wide range of genomic features. Among the VNTR-type markers, there are examples of variation in a non-genic region, variation within an intron, and variation in the coding sequence of a gene. Among the SNP-based markers there are examples of polymorphism in intronic DNA and synonymous substitution in a coding sequence. Thus these markers can serve laboratory exercises in both transmission genetics and molecular biology.

Slankster, Eryn E.; Chase, Jillian M.; Jones, Lauren A.; Wendell, Douglas L.

2012-01-01

308

Development of new genomic microsatellite markers from robusta coffee ( Coffea canephora Pierre ex A. Froehner) showing broad cross-species transferability and utility in genetic studies  

Microsoft Academic Search

Background  Species-specific microsatellite markers are desirable for genetic studies and to harness the potential of MAS-based breeding\\u000a for genetic improvement. Limited availability of such markers for coffee, one of the most important beverage tree crops, warrants\\u000a newer efforts to develop additional microsatellite markers that can be effectively deployed in genetic analysis and coffee\\u000a improvement programs. The present study aimed to develop

Prasad Suresh Hendre; Regur Phanindranath; V Annapurna; Albert Lalremruata; Ramesh K Aggarwal

2008-01-01

309

Determination of genetic relationships between evergreen azalea cultivars in China using AFLP markers*  

PubMed Central

Evergreen azaleas are among the most important ornamental shrubs in China. Today, there are probably over 300 cultivars preserved in different nurseries, but with little information available on the cultivar itself or relationships between cultivars. Amplified fragment length polymorphism (AFLP) markers were employed to determine the genetic relationships between evergreen azalea cultivars in China. One hundred and thirty genotypes collected from gardens and nurseries, including cultivars classified in the groups East, West, Hairy, and Summer, unknown cultivars, and close species, were analyzed using three primer pairs. A total of 408 polymorphic fragments were generated by AFLP reactions with an average of 136 fragments per primer pair. The average values of expected heterozygosity and Shannon’s information index were 0.3395 and 0.5153, respectively. Genetic similarities were generated based on Dice coefficients, used to construct a neighbor joining tree, and bootstrapped for 100 replicates in Treecon V1.3b. Principal coordinate analysis (PCO) was performed based on Dice distances using NTSYS-pc software. The AFLP technique was useful for analyzing genetic diversity in evergreen azaleas. Cluster analysis revealed that cultivars in the West and Summer groups were quite distinct from other groups in the four-group classification system and that the East and Hairy groups should be redefined.

Zhou, Hong; Liao, Jin; Xia, Yi-ping; Teng, Yuan-wen

2013-01-01

310

Genetic variability in maned wolf based on heterologous short-tandem repeat markers from domestic dog.  

PubMed

The maned wolf (Chrysocyon brachyurus) is the largest South American canid. Habitat loss and fragmentation, due to agricultural expansion and predatory hunting, are the main threats to this species. It is included in the official list of threatened wildlife species in Brazil, and is also protected by IUCN and CITES. Highly variable genetic markers such as microsatellites have the potential to resolve genetic relationships at all levels of the population structure (among individuals, demes or metapopulations) and also to identify the evolutionary unit for strategies for the conservation of the species. Tests were carried out to verify whether a class of highly polymorphic tetranucleotide repeats described for the domestic dog effectively amplifies DNA in the maned wolf. All five loci studied were amplified; however, one of these, was shown to be monomorphic in 69 maned wolf samples. The average allele number and estimated heterozygosity per polymorphic locus were 4.3 and 67%, respectively. The genetic variability found for this species, which is considered threatened with extinction, showed similar results when compared to studies of other canids. PMID:17624858

Salim, D C; Akimoto, A A; Carvalho, C B; Oliveira, S F; Grisolia, C K; Moreira, J R; Klautau-Guimarães, M N

2007-06-20

311

Genetic diversity among melon accessions (Cucumis melo) from Turkey based on SSR markers.  

PubMed

Melon (Cucumis melo) is an important vegetable crop in Turkey, where it is grown in many regions; the most widely planted lines are local winter types belonging to the var. inodorous. We examined 81 melon genotypes collected from different provinces of Turkey, compared with 15 reference melon genotypes obtained from INRA/France, to determine genetic diversity among Turkish melons. Twenty polymorphic primers were used to generate the SSR markers. PCR amplification was performed and electrophoresis was conducted. SSR data were used to generate a binary matrix. For cluster analysis, UPGMA was employed to construct a clustering dendrogram based on the genetic distance matrix. The cophenetic correlation was compared with the similarity matrix using the Mantel matrix correspondence test to evaluate the representativeness of the dendrogram. A total of 123 alleles were amplified using the 20 SSR primer sets. The number of alleles detected by a single primer set ranged from 2 to 12, with an average of 6.15. The similarity ranged from 0.22 to 1.00 in the dendrogram developed from microsatellite analysis. Based on this molecular data, we concluded that genetic diversity among these Turkish accessions is relatively high. PMID:23315810

Kaçar, Y A; Simsek, O; Solmaz, I; Sari, N; Mendi, Y Y

2012-12-19

312

The analysis of genetic diversity and differentiation of six Chinese cattle populations using microsatellite markers.  

PubMed

A total of 321 individuals from six cattle populations of four species in a bovine subfamily in China were studied using 12 pairs of microsatellite markers. The genetic diversities within and between populations were calculated. The phylogenetic trees were constructed by (delta mu)(2) and DA distances, and the divergence times between populations were estimated by (delta mu)(2). Altogether, 144 microsatellite alleles were detected including 24 private alleles and nine shared alleles. Chinese Holstein had the largest number of private alleles (10), whereas, Bohai black and Buffalo had the smallest number of private alleles (2). Chinese Holstein showed the highest genetic variability. Its observed number of alleles (Na), mean effective number of alleles (MNA), and mean heterozygosity (He) were 7.7500, 4.9722, and 0.7719, respectively, whereas, the Buffalo and Yak showed low genetic variability. In the phylogenetic trees, Luxi and Holstein grouped first, followed by Bohai and Minnan. Yak branched next and buffalo emerged as the most divergent population from other cattle populations. Luxi and Bohai were estimated to have diverged 0.039-0.105 million years ago (MYA), however, buffalo and Holstein diverged 0.501-1.337 MYA. The divergence time of Yak versus Minnan, Holstein and buffalo was 0.136-0.363, 0.273-0.729, and 0.326-0.600 MYA, respectively. PMID:18222406

Mao, Yongjiang; Chang, Hong; Yang, Zhangping; Zhang, Liu; Xu, Ming; Chang, Guobin; Sun, Wei; Song, Guangming; Ji, Dejun

2008-01-01

313

Genetic diversity and molecular markers in introduced and Thai native apple snails (Pomacea and Pila).  

PubMed

The genetic diversity and species-diagnostic markers in the introduced apple snail, Pomacea canaliculata and in the native Thai apple snails; Pila ampullacea, P. angelica, P. pesmei, and P. polita, were investigated by restriction analysis of COI and are reported for the first time. Twenty-one composite haplotypes showing non-overlapping distributions among species were found. Genetic heterogeneity analysis indicated significant differences between species (P < 0.0001) and within P. pesmei (P < 0.0001) and P. angelica (P < 0.0004). No such heterogeneity was observed in Pomacea canaliculata (P > 0.0036 as modified by the Bonferroni procedure), P. ampullacea (P = 0.0824-1.000) and P. polita (P = 1.0000). A neighbor-joining tree based on genetic distance between pairs of composite haplotypes differentiated all species and indicated that P. angelica and P. pesmei are closely related phylogenetically. In addition, the 16S rDNA of these species was cloned and sequenced. A species-specific PCR for P. canaliculata was successfully developed with a sensitivity of detection of approximately 50 pg of the target DNA template. The amplification of genomic DNA (50 pg and 25 ng) isolated from the fertilized eggs, and juveniles (1, 7, and 15 d after hatching) of Pomacea canaliculata was also successful, and suggested that Pomacea canaliculata and Pila species can be discriminated from the early stages of development. PMID:15469739

Thaewnon-ngiw, Bungorn; Klinbunga, Sirawut; Phanwichien, Kantimanee; Sangduen, Nitsri; Lauhachinda, Nitaya; Menasveta, Piamsak

2004-07-31

314

Assessment of the genetic diversity and phylogenetic relationships of a temperate bamboo collection by using transferred EST-SSR markers.  

PubMed

Polymorphic expressed sequence tag - simple sequence repeat (EST-SSR) markers derived from major cereal crops were used to assess the genetic diversity of the USDA temperate bamboo collection consisting of 92 accessions classified in 11 separate genera and 44 species. A total of 211 bands were detected with a mean number of alleles per locus of 8.440. Phylogenetic relationships were determined by calculating genetic distances between all pairwise combinations and assessing differences in character data. The resulting dendrograms (unweighted pair group method with arithmetic means (UPGMA) and parsimony) clustered the accessions into 2 main clades, which corresponded to accessions characterized morphologically as either clumping (sympodial) or running (monopodial) bamboos. The majority of the accessions clustered according to their current taxonomic classification. These markers were also beneficial in identifying contaminated and (or) misidentified plots. Overall, these transferred markers were informative in differentiating the various bamboo accessions and determining the level of genetic variation within and among species and genera. PMID:16094440

Barkley, N A; Newman, M L; Wang, M L; Hotchkiss, M W; Pederson, G A

2005-08-01

315

Comparative use of InDel and SSR markers in deciphering the interspecific structure of cultivated citrus genetic diversity: a perspective for genetic association studies.  

PubMed

Genetic stratification associated with domestication history is a key parameter for estimating the pertinence of genetic association study within a gene pool. Previous molecular and phenotypic studies have shown that most of the diversity of cultivated citrus results from recombination between three main species: C. medica (citron), C. reticulata (mandarin) and C. maxima (pummelo). However, the precise contribution of each of these basic species to the genomes of secondary cultivated species, such as C. sinensis (sweet orange), C. limon (lemon), C. aurantium (sour orange), C. paradisi (grapefruit) and recent hybrids is unknown. Our study focused on: (1) the development of insertion-deletion (InDel) markers and their comparison with SSR markers for use in genetic diversity and phylogenetic studies; (2) the analysis of the contributions of basic taxa to the genomes of secondary species and modern cultivars and (3) the description of the organisation of the Citrus gene pool, to evaluate how genetic association studies should be done at the cultivated Citrus gene pool level. InDel markers appear to be better phylogenetic markers for tracing the contributions of the three ancestral species, whereas SSR markers are more useful for intraspecific diversity analysis. Most of the genetic organisation of the Citrus gene pool is related to the differentiation between C. reticulata, C. maxima and C. medica. High and generalised LD was observed, probably due to the initial differentiation between the basic species and a limited number of interspecific recombinations. This structure precludes association genetic studies at the genus level without developing additional recombinant populations from interspecific hybrids. Association genetic studies should also be affordable at intraspecific level in a less structured pool such as C. reticulata. PMID:22160318

García-Lor, Andrés; Luro, François; Navarro, Luis; Ollitrault, Patrick

2011-12-11

316

Genetic characterization of an elite coffee germplasm assessed by gSSR and EST-SSR markers.  

PubMed

Coffee is one of the main agrifood commodities traded worldwide. In 2009, coffee accounted for 6.1% of the value of Brazilian agricultural production, generating a revenue of US$6 billion. Despite the importance of coffee production in Brazil, it is supported by a narrow genetic base, with few accessions. Molecular differentiation and diversity of a coffee breeding program were assessed with gSSR and EST-SSR markers. The study comprised 24 coffee accessions according to their genetic origin: arabica accessions (six traditional genotypes of C. arabica), resistant arabica (six leaf rust-resistant C. arabica genotypes with introgression of Híbrido de Timor), robusta (five C. canephora genotypes), Híbrido de Timor (three C. arabica x C. canephora), triploids (three C. arabica x C. racemosa), and racemosa (one C. racemosa). Allele and polymorphism analysis, AMOVA, the Student t-test, Jaccard's dissimilarity coefficient, cluster analysis, correlation of genetic distances, and discriminant analysis, were performed. EST-SSR markers gave 25 exclusive alleles per genetic group, while gSSR showed 47, which will be useful for differentiating accessions and for fingerprinting varieties. The gSSR markers detected a higher percentage of polymorphism among (35% higher on average) and within (42.9% higher on average) the genetic groups, compared to EST-SSR markers. The highest percentage of polymorphism within the genetic groups was found with gSSR markers for robusta (89.2%) and for resistant arabica (39.5%). It was possible to differentiate all genotypes including the arabica-related accessions. Nevertheless, combined use of gSSR and EST-SSR markers is recommended for coffee molecular characterization, because EST-SSRs can provide complementary information. PMID:22002130

Missio, R F; Caixeta, E T; Zambolim, E M; Pena, G F; Zambolim, L; Dias, L A S; Sakiyama, N S

2011-10-06

317

Genetic maps of SSR and SRAP markers in diploid orchardgrass (Dactylis glomerata L.) using the pseudo-testcross strategy.  

PubMed

Orchardgrass (Dactylis glomerata L.) is one of the most important cool-season forage grasses commonly grown throughout the temperate regions of the world. The objective of this work was to construct a diploid (2n = 2x = 14) orchardgrass genetic linkage map useful as a framework for basic genetic studies and plant breeding. A combination of simple sequence repeat (SSR) and sequence-related amplified polymorphism (SRAP) molecular markers were used for map construction. The linkage relationships among 164 SSRs and 108 SRAPs, assayed in a pseudo-testcross F1 segregating population generated from a cross between two diploid parents, were used to construct male (01996) and female (YA02-103) parental genetic maps. The paternal genetic map contains 90 markers (57 SSRs and 33 SRAPs) over 9 linkage groups (LGs), and the maternal genetic map is composed of 87 markers (54 SSRs and 33 SRAPs) assembled over 10 LGs. The total map distance of the male map is 866.7 centimorgans (cM), representing 81% genome coverage, whereas the female map spans 772.0 cM, representing 75% coverage. The mean map distance between markers is 9.6 cM in the male map and 8.9 cM in the female map. About 14% of the markers remained unassigned. The level of segregation distortion observed in this cross was 15%. Homology between the two maps was established between five LGs of the male map and five LGs of the female map using 10 bridging markers. The information presented in this study establishes a foundation for extending genetic mapping in this species, serves as a framework for mapping quantitative trait loci (QTLs), and provides basic information for future molecular breeding studies. PMID:21423284

Xie, Wengang; Zhang, Xinquan; Cai, Hongwei; Huang, Linkai; Peng, Yan; Ma, Xiao

2011-03-01

318

Compatibility of pedigree-based and marker-based relationship matrices for single-step genetic evaluation  

PubMed Central

Background Single-step methods provide a coherent and conceptually simple approach to incorporate genomic information into genetic evaluations. An issue with single-step methods is compatibility between the marker-based relationship matrix for genotyped animals and the pedigree-based relationship matrix. Therefore, it is necessary to adjust the marker-based relationship matrix to the pedigree-based relationship matrix. Moreover, with data from routine evaluations, this adjustment should in principle be based on both observed marker genotypes and observed phenotypes, but until now this has been overlooked. In this paper, I propose a new method to address this issue by 1) adjusting the pedigree-based relationship matrix to be compatible with the marker-based relationship matrix instead of the reverse and 2) extending the single-step genetic evaluation using a joint likelihood of observed phenotypes and observed marker genotypes. The performance of this method is then evaluated using two simulated datasets. Results The method derived here is a single-step method in which the marker-based relationship matrix is constructed assuming all allele frequencies equal to 0.5 and the pedigree-based relationship matrix is constructed using the unusual assumption that animals in the base population are related and inbred with a relationship coefficient ? and an inbreeding coefficient ??/?2. Taken together, this ? parameter and a parameter that scales the marker-based relationship matrix can handle the issue of compatibility between marker-based and pedigree-based relationship matrices. The full log-likelihood function used for parameter inference contains two terms. The first term is the REML-log-likelihood for the phenotypes conditional on the observed marker genotypes, whereas the second term is the log-likelihood for the observed marker genotypes. Analyses of the two simulated datasets with this new method showed that 1) the parameters involved in adjusting marker-based and pedigree-based relationship matrices can depend on both observed phenotypes and observed marker genotypes and 2) a strong association between these two parameters exists. Finally, this method performed at least as well as a method based on adjusting the marker-based relationship matrix. Conclusions Using the full log-likelihood and adjusting the pedigree-based relationship matrix to be compatible with the marker-based relationship matrix provides a new and interesting approach to handle the issue of compatibility between the two matrices in single-step genetic evaluation.

2012-01-01

319

Characterization and comparison of EST-SSR and TRAP markers for genetic analysis of the Japanese persimmon Diospyros kaki.  

PubMed

We developed and characterized expressed sequence tags (ESTs)-simple sequence repeats (SSRs) and targeted region amplified polymorphism (TRAP) markers to examine genetic relationships in the persimmon genus Diospyros gene pool. In total, we characterized 14 EST-SSR primer pairs and 36 TRAP primer combinations, which were amplified across 20 germplasms of 4 species in the genus Diospyros. We used various genetic parameters, including effective multiplex ratio (EMR), diversity index (DI), and marker index (MI), to test the utility of these markers. TRAP markers gave higher EMR (24.85) but lower DI (0.33), compared to EST-SSRs (EMR = 3.65, DI = 0.34). TRAP gave a very high MI (8.08), which was about 8 times than the MI of EST-SSR (1.25). These markers were utilized for phylogenetic inference of 20 genotypes of Diospyros kaki Thunb. and allied species, with a result that all kaki genotypes clustered closely and 3 allied species formed an independent group. These markers could be further exploited for large-scale genetic relationship inference. PMID:23359055

Luo, C; Zhang, F; Zhang, Q L; Guo, D Y; Luo, Z R

2013-01-09

320

Genetic markers for analysing symbiotic relationships and lateral gene transfer in Neotropical bradyrhizobia.  

PubMed

Assays with seven sets of lineage-specific polymerase chain reaction (PCR) primers in the ribosomal RNA region were performed on 96 isolates of the Bradyrhizobium sp. nodule bacteria from Barro Colorado Island, Panama. The isolates were derived from 10 legume host species in six genera (Centrosema, Desmodium, Dioclea, Inga, Machaerium and Vigna). The PCR assays differentiated 13 composite genotypes, and sequencing of a 5' 23S rRNA region indicated that all but one had a unique sequence. The most common genotype (seen in 44% of the isolates) was associated with all six legume host genera, and had a marker profile and 5' 23S rRNA sequence identical to a Bradyrhizobium lineage associated with several other legume genera in Panama and Costa Rica. Another 46% of the isolates had genotypes found to be associated with two to three legume genera. Bradyrhizobium strains with low host specificity thus appear to be prevalent in this tropical forest. Based on 16S rRNA and 5' 23S rRNA markers, most of the isolates had clear affinities to either B. japonicum or B. elkanii. However, one strain (Cp5-3) with a B. elkanii-type 16S rRNA marker had a 5' 23S rRNA region resembling B. japonicum. A partition homogeneity test indicated that relationships of strain Cp5-3 were significantly discordant for 16S rRNA vs. 23S rRNA sequences, and a runs test detected significant mosaic structure across the rRNA region. Lateral gene transfer events have therefore played a role in the evolution of symbiotic bacteria in this environment. PMID:12919482

Parker, M A

2003-09-01

321

Construction of a Genetic Linkage Map Based on Amplified Fragment Length Polymorphism Markers and Development of Sequence-Tagged Site Markers for Marker-Assisted Selection of the Sporeless Trait in the Oyster Mushroom (Pleurotus eryngii)  

PubMed Central

A large number of spores from fruiting bodies can lead to allergic reactions and other problems during the cultivation of edible mushrooms, including Pleurotus eryngii (DC.) Quél. A cultivar harboring a sporulation-deficient (sporeless) mutation would be useful for preventing these problems, but traditional breeding requires extensive time and labor. In this study, using a sporeless P. eryngii strain, we constructed a genetic linkage map to introduce a molecular breeding program like marker-assisted selection. Based on the segregation of 294 amplified fragment length polymorphism markers, two mating type factors, and the sporeless trait, the linkage map consisted of 11 linkage groups with a total length of 837.2 centimorgans (cM). The gene region responsible for the sporeless trait was located in linkage group IX with 32 amplified fragment length polymorphism markers and the B mating type factor. We also identified eight markers closely linked (within 1.2 cM) to the sporeless locus using bulked-segregant analysis-based amplified fragment length polymorphism. One such amplified fragment length polymorphism marker was converted into two sequence-tagged site markers, SD488-I and SD488-II. Using 14 wild isolates, sequence-tagged site analysis indicated the potential usefulness of the combination of two sequence-tagged site markers in cross-breeding of the sporeless strain. It also suggested that a map constructed for P. eryngii has adequate accuracy for marker-assisted selection.

Ueda, Jun; Obatake, Yasushi; Murakami, Shigeyuki; Fukumasa, Yukitaka; Matsumoto, Teruyuki

2012-01-01

322

Construction of a genetic linkage map based on amplified fragment length polymorphism markers and development of sequence-tagged site markers for marker-assisted selection of the sporeless trait in the oyster mushroom (Pleurotus eryngii).  

PubMed

A large number of spores from fruiting bodies can lead to allergic reactions and other problems during the cultivation of edible mushrooms, including Pleurotus eryngii (DC.) Quél. A cultivar harboring a sporulation-deficient (sporeless) mutation would be useful for preventing these problems, but traditional breeding requires extensive time and labor. In this study, using a sporeless P. eryngii strain, we constructed a genetic linkage map to introduce a molecular breeding program like marker-assisted selection. Based on the segregation of 294 amplified fragment length polymorphism markers, two mating type factors, and the sporeless trait, the linkage map consisted of 11 linkage groups with a total length of 837.2 centimorgans (cM). The gene region responsible for the sporeless trait was located in linkage group IX with 32 amplified fragment length polymorphism markers and the B mating type factor. We also identified eight markers closely linked (within 1.2 cM) to the sporeless locus using bulked-segregant analysis-based amplified fragment length polymorphism. One such amplified fragment length polymorphism marker was converted into two sequence-tagged site markers, SD488-I and SD488-II. Using 14 wild isolates, sequence-tagged site analysis indicated the potential usefulness of the combination of two sequence-tagged site markers in cross-breeding of the sporeless strain. It also suggested that a map constructed for P. eryngii has adequate accuracy for marker-assisted selection. PMID:22210222

Okuda, Yasuhito; Ueda, Jun; Obatake, Yasushi; Murakami, Shigeyuki; Fukumasa, Yukitaka; Matsumoto, Teruyuki

2011-12-30

323

Annotated genetic linkage maps of Pinus pinaster Ait. from a Central Spain population using microsatellite and gene based markers  

PubMed Central

Background Pinus pinaster Ait. is a major resin producing species in Spain. Genetic linkage mapping can facilitate marker-assisted selection (MAS) through the identification of Quantitative Trait Loci and selection of allelic variants of interest in breeding populations. In this study, we report annotated genetic linkage maps for two individuals (C14 and C15) belonging to a breeding program aiming to increase resin production. We use different types of DNA markers, including last-generation molecular markers. Results We obtained 13 and 14 linkage groups for C14 and C15 maps, respectively. A total of 211 and 215 markers were positioned on each map and estimated genome length was between 1,870 and 2,166 cM respectively, which represents near 65% of genome coverage. Comparative mapping with previously developed genetic linkage maps for P. pinaster based on about 60 common markers enabled aligning linkage groups to this reference map. The comparison of our annotated linkage maps and linkage maps reporting QTL information revealed 11 annotated SNPs in candidate genes that co-localized with previously reported QTLs for wood properties and water use efficiency. Conclusions This study provides genetic linkage maps from a Spanish population that shows high levels of genetic divergence with French populations from which segregating progenies have been previously mapped. These genetic maps will be of interest to construct a reliable consensus linkage map for the species. The importance of developing functional genetic linkage maps is highlighted, especially when working with breeding populations for its future application in MAS for traits of interest.

2012-01-01

324

Comparison of DNA marker and pedigree-based methods of genetic analysis of plantain and banana (Musa spp.) clones. I. estimation of genetic relationships  

Microsoft Academic Search

Traditional approaches to the breeding of Musa crops are highly demanding in terms of both time and space. However, the application of molecular genetic analysis may dramatically\\u000a improve breeding efficiency. The objectives of the present study were to compare pedigree and DNA marker methods of estimating\\u000a genetic relationships across and within generations among diploid, triploid and tetraploid accessions of plantain

A. Tenkouano; J. H. Crouch; H. K. Crouch; D. Vuylsteke; R. Ortiz

1999-01-01

325

Evaluation of genetic variability and mutation drift equilibrium of Banni buffalo using multi locus microsatellite markers.  

PubMed

The present study was conducted to evaluate genetic diversity of Banni buffalo and its relationship/differentiation with Murrah using genotypic data on 24 heterologus bovine specific microsatellite marker loci. A total of 138 alleles were observed with a mean of 5.75 alleles/locus across two populations. The mean observed and expected heterozygosities were found to be 0.441 and 0.572 respectively in Banni buffaloes while it was 0.464 and 0.610 respectively in Murrah buffaloes. The average heterozygosity deficit was significantly positive with substantially higher values observed in Banni (22.3%) and Murrah (24%) buffalo populations. Banni buffalo population, when evaluated for mutation drift equilibrium revealed significant heterozygosity excess under IAM while no such excess was observed under SMM and TPM. The qualitative graphical test revealed a normal L-shaped distribution of allele frequencies indicating the absence of genetic bottleneck in Banni buffaloes. The mean estimates of F-statistics over all the loci were 0.376 for F(IT), 0.187 for F(ST) and 0.232 for F(IS) respectively. Analysis of molecular variance (AMOVA) revealed 18.95% of the total variation being explained by between breed differences while 14.36% of the variation explained differences between individuals within each breed. Genotype assignment test revealed distinct clustering of Banni and Murrah buffaloes. Genetic distance was estimated using three different methods, the results of which revealed considerable genetic differentiation between these two buffalo populations. The divergence time between Banni and Murrah buffaloes was estimated to be around 7286 years. The results of the present study may be helpful in decision making for conservation programs as Banni buffalo population is on decline. PMID:19130283

Mishra, B P; Kataria, R S; Kathiravan, P; Bulandi, S S; Singh, K P; Sadana, D K

2009-01-09

326

Simple sequence repeat (SSR) markers survey of the cassava (Manihot esculenta Crantz) genome: towards an SSR-based molecular genetic map of cassava  

Microsoft Academic Search

The development of PCR-based, easily automated molecular genetic markers, such as SSR markers, are required for realistic\\u000a cost-effective marker-assisted selection schemes. This paper describes the development and characterization of 172 new SSR\\u000a markers for the cassava genome. The placement of 36 of these markers on the existing RFLP framework map of cassava is also\\u000a reported. Two similar enrichment methods were

P. Stephenson; K. Edwards; S. Melzer; J. Nkumbira; U. Gullberg; K. Apel; M. Gale; J. Tohme; M. Fregene

2001-01-01

327

Genetic make up and structure of Colombian populations by means of uniparental and biparental DNA markers.  

PubMed

Colombia is a country with great geographic heterogeneity and marked regional differences in pre-Columbian native population density and in the extent of past African and European immigration. As a result, Colombia has one of the most diverse populations in Latin America. Here we evaluated ancestry in over 1,700 individuals from 24 Colombian populations using biparental (autosomal and X-Chromosome), maternal (mtDNA), and paternal (Y-chromosome) markers. Autosomal ancestry varies markedly both within and between regions, confirming the great genetic diversity of the Colombian population. The X-chromosome, mtDNA, and Y-chromosome data indicate that there is a pattern across regions indicative of admixture involving predominantly Native American women and European and African men. PMID:20734436

Rojas, Winston; Parra, María Victoria; Campo, Omer; Caro, María Antonieta; Lopera, Juan Guillermo; Arias, William; Duque, Constanza; Naranjo, Andrés; García, Jharley; Vergara, Candelaria; Lopera, Jaime; Hernandez, Erick; Valencia, Ana; Caicedo, Yuri; Cuartas, Mauricio; Gutiérrez, Javier; López, Sergio; Ruiz-Linares, Andrés; Bedoya, Gabriel

2010-09-01

328

Relationship between genetic risk factors and markers for Alzheimer's disease pathology.  

PubMed

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by neuritic plaques (main constituent: ?-amyloid [A?]) and neurofibrillary tangles (hyperphosphorylated tau protein) in the brain. Abnormalities in A? and tau can be measured upon neuropathological examination, in cerebrospinal fluid or by PET. Etiologically, a growing body of evidence suggests that susceptibility to AD is genetically controlled. However, the precise nature of the underlying risk genes and their relation to AD biomarkers remains largely elusive. To this end, we performed a qualitative review of 17 studies (covering 47 polymorphisms in 26 genes) and investigated the potential relation between the most compelling AD risk genes and markers for A? and tau in cerebrospinal fluid, PET imaging and neuropathological examination. Of all covered genes, only APOE and PICALM showed consistent effects on A? but not on tau, while no obvious effects were observed for CLU, CR1, ACE, SORL and MAPT. PMID:22917148

Elias-Sonnenschein, Lyzel S; Bertram, Lars; Visser, Pieter Jelle

2012-08-01

329

Genetic variation in a wild population of the 'sleep' passion fruit (Passiflora setacea) based on molecular markers.  

PubMed

Little is known about the molecular genetic diversity of most Passiflora species. We used RAPD markers to evaluate the genetic diversity of 24 genotypes of the 'sleep' passion fruit (Passiflora setacea). Twelve primers generated 95 markers, 88% of which were polymorphic. The genetic distance estimated by the complement of the Dice index ranged from 0.29 (among accessions Ps-G1 and Ps-G13) to 0.69 (among accessions Ps-G21 and Ps-G23). Genotype grouping based on the UPGMA algorithm showed considerable variability among genotypes. We conclude that P. setacea has a broad genetic base that could be exploited in breeding programs. PMID:22576831

Cerqueira-Silva, C B M; Santos, E S L; Conceição, L D H C S; Cardoso-Silva, C B; Pereira, A S; Oliveira, A C; Corrêa, R X

2012-03-22

330

Resistance to Tellurite as a Selection Marker for Genetic Manipulations of Pseudomonas Strains  

PubMed Central

Resistance to the toxic compound potassium tellurite (Telr) has been employed as a selection marker built into a set of transposon vectors and broad-host-range plasmids tailored for genetic manipulations of Pseudomonas strains potentially destined for environmental release. In this study, the activated Telr determinants encoded by the cryptic telAB genes of plasmid RK2 were produced, along with the associated kilA gene, as DNA cassettes compatible with cognate vectors. In one case, the Telr determinants were assembled between the I and O ends of a suicide delivery vector for mini-Tn5 transposons. In another case, the kilA and telAB genes were combined with a minimal replicon derived from a variant of Pseudomonas plasmid pPS10, which is able to replicate in a variety of gram-negative hosts and is endowed with a modular collection of cloning and expression assets. Either in the plasmid or in the transposon vector, the Telr marker was combined with a 12-kb DNA segment of plasmid pWW0 of Pseudomonas putida mt-2 encoding the upper TOL pathway enzymes. This allowed construction of antibiotic resistance-free but selectable P. putida strains with the ability to grow on toluene as the sole carbon source through an ortho-cleavage catabolic pathway.

Sanchez-Romero, Juan M.; Diaz-Orejas, Ramon; De Lorenzo, Victor

1998-01-01

331

Genetic characterization of a collection of chayote, Sechium edule (Jacq.) Swartz, in Costa Rica by using isozyme markers  

Microsoft Academic Search

We established protocols for the analysis of genetic diversity in chayote (Sechium edule) by using isozyme markers, thereby determining the level of genetic diversity present in 42 accessions of chayote from Costa\\u000a Rica. We obtained clear and reproducible zymograms for eight enzyme staining systems: PGM, 6-PGD, PGI, IDH, MDH, SOD, SKD,\\u000a and EST, and were able to score 14 putative

Ana Abdelnour; Oscar J. Rocha

2008-01-01

332

Application of random amplified polymorphic DNA (RAPD) markers to evaluate intraspecific genetic variation in red mullet (Mullus barbatus)  

Microsoft Academic Search

The random amplified polymorphic DNA (RAPD) technique was used to evaluate genetic affinities among eight red mullet (Mullus barbatus L., 1758) samples from the Mediterranean Sea. Twenty-nine random primers were used. Despite the variability which was found\\u000a within samples, no specific RAPD marker for the discrimination of the populations was detected. The data analysis revealed\\u000a that the genetic diversity among

Z. Mamuris; A. P. Apostolidis; A. J. Theodorou; C. Triantaphyllidis

1998-01-01

333

Construction of two genetic linkage maps in cultivated tetraploid alfalfa (Medicago sativa) using microsatellite and AFLP markers  

PubMed Central

Background Alfalfa (Medicago sativa) is a major forage crop. The genetic progress is slow in this legume species because of its autotetraploidy and allogamy. The genetic structure of this species makes the construction of genetic maps difficult. To reach this objective, and to be able to detect QTLs in segregating populations, we used the available codominant microsatellite markers (SSRs), most of them identified in the model legume Medicago truncatula from EST database. A genetic map was constructed with AFLP and SSR markers using specific mapping procedures for autotetraploids. The tetrasomic inheritance was analysed in an alfalfa mapping population. Results We have demonstrated that 80% of primer pairs defined on each side of SSR motifs in M. truncatula EST database amplify with the alfalfa DNA. Using a F1 mapping population of 168 individuals produced from the cross of 2 heterozygous parental plants from Magali and Mercedes cultivars, we obtained 599 AFLP markers and 107 SSR loci. All but 3 SSR loci showed a clear tetrasomic inheritance. For most of the SSR loci, the double-reduction was not significant. For the other loci no specific genotypes were produced, so the significant double-reduction could arise from segregation distortion. For each parent, the genetic map contained 8 groups of four homologous chromosomes. The lengths of the maps were 2649 and 3045 cM, with an average distance of 7.6 and 9.0 cM between markers, for Magali and Mercedes parents, respectively. Using only the SSR markers, we built a composite map covering 709 cM. Conclusions Compared to diploid alfalfa genetic maps, our maps cover about 88–100% of the genome and are close to saturation. The inheritance of the codominant markers (SSR) and the pattern of linkage repulsions between markers within each homology group are consistent with the hypothesis of a tetrasomic meiosis in alfalfa. Except for 2 out of 107 SSR markers, we found a similar order of markers on the chromosomes between the tetraploid alfalfa and M. truncatula genomes indicating a high level of colinearity between these two species. These maps will be a valuable tool for alfalfa breeding and are being used to locate QTLs.

Julier, Bernadette; Flajoulot, Sandrine; Barre, Philippe; Cardinet, Gaelle; Santoni, Sylvain; Huguet, Thierry; Huyghe, Christian

2003-01-01

334

Population structure and genetic diversity in a commercial maize breeding program assessed with SSR and SNP markers  

PubMed Central

Information about the genetic diversity and population structure in elite breeding material is of fundamental importance for the improvement of crops. The objectives of our study were to (a) examine the population structure and the genetic diversity in elite maize germplasm based on simple sequence repeat (SSR) markers, (b) compare these results with those obtained from single nucleotide polymorphism (SNP) markers, and (c) compare the coancestry coefficient calculated from pedigree records with genetic distance estimates calculated from SSR and SNP markers. Our study was based on 1,537 elite maize inbred lines genotyped with 359 SSR and 8,244 SNP markers. The average number of alleles per locus, of group specific alleles, and the gene diversity (D) were higher for SSRs than for SNPs. Modified Roger’s distance (MRD) estimates and membership probabilities of the STRUCTURE matrices were higher for SSR than for SNP markers but the germplasm organization in four heterotic pools was consistent with STRUCTURE results based on SSRs and SNPs. MRD estimates calculated for the two marker systems were highly correlated (0.87). Our results suggested that the same conclusions regarding the structure and the diversity of heterotic pools could be drawn from both markers types. Furthermore, although our results suggested that the ratio of the number of SSRs and SNPs required to obtain MRD or D estimates with similar precision is not constant across the various precision levels, we propose that between 7 and 11 times more SNPs than SSRs should be used for analyzing population structure and genetic diversity. Electronic supplementary material The online version of this article (doi:10.1007/s00122-009-1256-2) contains supplementary material, which is available to authorized users.

Van Inghelandt, Delphine; Melchinger, Albrecht E.; Lebreton, Claude

2010-01-01

335

Isolated chromosomes as a new and efficient source of DArT markers for the saturation of genetic maps.  

PubMed

We describe how the diversity arrays technology (DArT) can be coupled with chromosome sorting to increase the density of genetic maps in specific genome regions. Chromosome 3B and the short arm of chromosome 1B (1BS) of wheat were isolated by flow cytometric sorting and used to develop chromosome- and chromosome arm-enriched genotyping arrays containing 2,688 3B clones and 384 1BS clones. Linkage analysis showed that 553 of the 711 polymorphic 3B-derived markers (78%) mapped to chromosome 3B, and 59 of the 68 polymorphic 1BS-derived markers (87%) mapped to chromosome 1BS, confirming the efficiency of the chromosome-sorting approach. To demonstrate the potential for saturation of genetic maps, we constructed a consensus map of chromosome 3B using 19 mapping populations, including some that were genotyped with the 3B-enriched array. The 3B-derived DArT markers doubled the number of genetic loci covered. The resulting consensus map, probably the densest genetic map of 3B available to this date, contains 939 markers (779 DArTs and 160 other markers) that segregate on 304 genetically distinct loci. Importantly, only 2,688 3B-derived clones (probes) had to be screened to obtain almost twice as many polymorphic 3B markers (510) as identified by screening approximately 70,000 whole genome-derived clones (269). Since an enriched DArT array can be developed from less than 5 ng of chromosomal DNA, a quantity which can be obtained within 1 h of sorting, this approach can be readily applied to any crop for which chromosome sorting is available. PMID:20364376

Wenzl, Peter; Suchánková, Pavla; Carling, Jason; Simková, Hana; Huttner, Eric; Kubaláková, Marie; Sourdille, Pierre; Paul, Edie; Feuillet, Catherine; Kilian, Andrzej; Dolezel, Jaroslav

2010-04-04

336

Genetic Linkage Maps of Eucalyptus Grandis and Eucalyptus Urophylla Using a Pseudo-Testcross: Mapping Strategy and Rapd Markers  

PubMed Central

We have used a ``two-way pseudo-testcross'' mapping strategy in combination with the random amplified polymorhic DNA (RAPD) assay to construct two moderate density genetic linkage maps for species of Eucalyptus. In the cross between two heterozygous individuals many single-dose RAPD markers will be heterozygous in one parent, null in the other and therefore segregate 1:1 in their F(1) progeny following a testcross configuration. Meiosis and gametic segregation in each individual can be directly and efficiently analyzed using RAPD markers. We screened 305 primers of arbitrary sequence, and selected 151 to amplify a total of 558 markers. These markers were grouped at LOD 5.0, ? = 0.25, resulting in the maternal Eucalyptus grandis map having a total of 240 markers into 14 linkage groups (1552 cM) and the paternal Eucalyptus urophylla map with 251 markers in 11 linkage groups (1101 cM) (n = 11 in Eucalyptus). Framework maps ordered with a likelihood support >/=1000:1 were assembled covering 95% of the estimated genome size in both individuals. Characterization of genome complexity of a sample of 48 mapped random amplified polymorphic DNA (RAPD) markers indicate that 53% amplify from low copy regions. These are the first reported high coverage linkage maps for any species of Eucalyptus and among the first for any hardwood tree species. We propose the combined use of RAPD markers and the pseudo-testcross configuration as a general strategy for the construction of single individual genetic linkage maps in outbred forest trees as well as in any highly heterozygous sexually reproducing living organism. A survey of the occurrence of RAPD markers in different individuals suggests that the pseudo-testcross/RAPD mapping strategy should also be efficient at the intraspecific level and increasingly so with crosses of genetically divergent individuals. The ability to quickly construct single-tree genetic linkage maps in any forest species opens the way for a shift from the paradigm of a species index map to the heterodox proposal of constructing several maps for individual trees of a population, therefore mitigating the problem of linkage equilibrium between marker and trait loci for the application of marker assisted strategies in tree breeding.

Grattapaglia, D.; Sederoff, R.

1994-01-01

337

Assessment of Genetic Stability of Propagated Plantlets of Four Sea Buckthorn (Hippophae) Cultivars and the Establishment of Genetic Relationships Between them by ISSR Markers  

Microsoft Academic Search

The common sea buckthorn or seaberry (Hippophae rhamnoides) is important environmentally, commercially, and as a new berry crop. Some morphological differences among mother plants and lines obtained by cuttings often lead a purchaser to question if the propagated plantlets are true-to-name cultivars. Intersimple sequence repeat (ISSR) markers were employed to assess the genetic stability of lines obtained by cuttings of

Qun Li; He Li; Cheng-Jiang Ruan; Xue-Ying Wang

2009-01-01

338

Genetic diversity studies in pea (Pisum sativum L.) using simple sequence repeat markers.  

PubMed

The genetic diversity among 28 pea (Pisum sativum L.) genotypes was analyzed using 32 simple sequence repeat markers. A total of 44 polymorphic bands, with an average of 2.1 bands per primer, were obtained. The polymorphism information content ranged from 0.657 to 0.309 with an average of 0.493. The variation in genetic diversity among these cultivars ranged from 0.11 to 0.73. Cluster analysis based on Jaccard's similarity coefficient using the unweighted pair-group method with arithmetic mean (UPGMA) revealed 2 distinct clusters, I and II, comprising 6 and 22 genotypes, respectively. Cluster II was further differentiated into 2 subclusters, IIA and IIB, with 12 and 10 genotypes, respectively. Principal component (PC) analysis revealed results similar to those of UPGMA. The first, second, and third PCs contributed 21.6, 16.1, and 14.0% of the variation, respectively; cumulative variation of the first 3 PCs was 51.7%. PMID:23546983

Kumari, P; Basal, N; Singh, A K; Rai, V P; Srivastava, C P; Singh, P K

2013-03-13

339

Uniparental Markers in Italy Reveal a Sex-Biased Genetic Structure and Different Historical Strata  

PubMed Central

Located in the center of the Mediterranean landscape and with an extensive coastal line, the territory of what is today Italy has played an important role in the history of human settlements and movements of Southern Europe and the Mediterranean Basin. Populated since Paleolithic times, the complexity of human movements during the Neolithic, the Metal Ages and the most recent history of the two last millennia (involving the overlapping of different cultural and demic strata) has shaped the pattern of the modern Italian genetic structure. With the aim of disentangling this pattern and understanding which processes more importantly shaped the distribution of diversity, we have analyzed the uniparentally-inherited markers in ?900 individuals from an extensive sampling across the Italian peninsula, Sardinia and Sicily. Spatial PCAs and DAPCs revealed a sex-biased pattern indicating different demographic histories for males and females. Besides the genetic outlier position of Sardinians, a North West–South East Y-chromosome structure is found in continental Italy. Such structure is in agreement with recent archeological syntheses indicating two independent and parallel processes of Neolithisation. In addition, date estimates pinpoint the importance of the cultural and demographic events during the late Neolithic and Metal Ages. On the other hand, mitochondrial diversity is distributed more homogeneously in agreement with older population events that might be related to the presence of an Italian Refugium during the last glacial period in Europe.

Sarno, Stefania; Harmant, Christine; Useli, Antonella; Sanz, Paula; Yang-Yao, Daniele; Manry, Jeremy; Ciani, Graziella; Luiselli, Donata; Quintana-Murci, Lluis; Comas, David; Pettener, Davide

2013-01-01

340

Genetic neighbourhood of clone structures in eelgrass meadows quantified by spatial autocorrelation of microsatellite markers.  

PubMed

Limited dispersal distances in plant populations frequently cause local genetic structure, which can be quantified by spatial autocorrelation. In clonal plants, three levels of spatial organization can contribute to positive autocorrelation; namely, the neighbourhood of (a) ramets, (b) clone fragments and (c) entire clones. Here we use data from an exhaustive sampling scheme on a clonal plant to measure the contribution of the neighbourhoods of each distinct clonal structure to total spatial autocorrelation. Four plots (256 grid points each) within dense meadows of the marine clonal plant Zostera marina (eelgrass) were sampled for clone structure with nine microsatellite markers ( approximately 80 alleles). We found significant coancestry (f(ij)), at all three levels of spatial organization, even when not allowing for joins between samples of identical genets. In addition, absolute values of f(ij) and the maximum distance with significant positive f(ij) decreased with the progressive exclusion of joins between alike genotypes. The neighbourhood of this clonal plant thus consists of three levels of organization, which are reflected in different kinship structures. Each of these kinship structures may affect the level of biparental inbreeding and the physical distance between flowering shoots and their outcrossing neighbourhood. These results also emphasize the notion that spatial autocorrelation crucially depends on the scale and intensity of sampling. PMID:14576737

Hämmerli, A; Reusch, T B H

2003-11-01

341

Discovery and characterization of novel genetic markers for use in the management of Lahontan cutthroat trout (Oncorhynchus clarkii henshawi).  

PubMed

The Lahontan cutthroat trout (Oncorhynchus clarkii henshawi) is threatened by habitat destruction, over-harvest and hybridization with nonnative trout. Currently, three Geographic Management Units (GMUs) are recognized within the taxon. Here, we describe a suite of 68 single-nucleotide polymorphism (SNP) genetic markers for use in the study and management of Lahontan cutthroat trout and a closely related subspecies, the Paiute cutthroat trout (O. c. seleneris). These include markers variable within the two subspecies (n = 35), diagnostic for the two subspecies (n = 23) and diagnostic for Yellowstone cutthroat trout (O. c. bouvieri) and other closely related subspecies (n = 10). Sixty-three markers were discovered by Sanger sequencing of 171 EST loci in an ascertainment panel including Lahontan cutthroat trout from four populations representing all GMUs. Five markers were identified in a secondary sequencing effort with a single population of Lahontan cutthroat trout. TaqMan assays were validated on six Lahontan cutthroat trout populations and a diverse panel of other trout. Over 90% of the markers variable in Lahontan cutthroat trout were polymorphic in at least two populations, and 66% were variable within all three GMUs. All Lahontan diagnostic markers were also fixed for the Lahontan allele in Paiute cutthroat trout. Most of the Yellowstone diagnostic markers can also be used for this purpose in other cutthroat trout subspecies. This is the first set of SNP markers to be developed for Lahontan cutthroat trout, and will be an important tool for conservation and management. PMID:23253773

Pritchard, Victoria L; Campbell, Nathan R; Narum, Shawn R; Peacock, Mary M; Garza, John Carlos

2012-12-17

342

Unexpected Genetic Diversity among and within Populations of the Toxic Dinoflagellate Alexandrium catenella as Revealed by Nuclear Microsatellite Markers?  

PubMed Central

Since 1998, blooms of Alexandrium catenella associated with paralytic shellfish poisoning have been repeatedly reported for Thau Lagoon (French Mediterranean coast). Based on data obtained for rRNA gene markers, it has been suggested that the strains involved could be closely related to the Japanese temperate Asian ribotype of the temperate Asian clade. In order to gain more insight into the origin of these organisms, we carried out a genetic analysis of 61 Mediterranean and 23 Japanese strains using both ribosomal and microsatellite markers. Whereas the phylogeny based on ribosomal markers tended to confirm the previous findings, the analysis of microsatellite sequences revealed an unexpected distinction between the French and Japanese populations. This analysis also highlighted great intraspecific diversity that was not detected with the classical rRNA gene markers. The Japanese strains are divided into two differentiated A. catenella lineages: the Sea of Japan lineage and the east coast lineage, which includes populations from the Inland Sea and the Pacific Ocean. A. catenella strains isolated from Thau Lagoon belong to another lineage. These findings indicate that microsatellite markers are probably better suited to investigations of the population genetics of this species that is distributed worldwide. Finally, application of the population genetics concepts available for macroorganisms could support new paradigms for speciation and migration in phytoplankton assemblages.

Masseret, Estelle; Grzebyk, Daniel; Nagai, Satoshi; Genovesi, Benjamin; Lasserre, Bernard; Laabir, Mohamed; Collos, Yves; Vaquer, Andre; Berrebi, Patrick

2009-01-01

343

An improved genetic linkage map for cowpea (Vigna unguiculata L.) combining AFLP, RFLP, RAPD, biochemical markers, and biological resistance traits.  

PubMed

An improved genetic linkage map has been constructed for cowpea (Vigna unguiculata L. Walp.) based on the segregation of various molecular markers and biological resistance traits in a population of 94 recombinant inbred lines (RILs) derived from the cross between 'IT84S-2049' and '524B'. A set of 242 molecular markers, mostly amplified fragment length polymorphism (AFLP), linked to 17 biological resistance traits, resistance genes, and resistance gene analogs (RGAs) were scored for segregation within the parental and recombinant inbred lines. These data were used in conjunction with the 181 random amplified polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP), AFLP, and biochemical markers previously mapped to construct an integrated linkage map for cowpea. The new genetic map of cowpea consists of 11 linkage groups (LGs) spanning a total of 2670 cM, with an average distance of 6.43 cM between markers. Astonishingly, a large, contiguous portion of LG1 that had been undetected in previous mapping work was discovered. This region, spanning about 580 cM, is composed entirely of AFLP markers (54 in total). In addition to the construction of a new map, molecular markers associated with various biological resistance and (or) tolerance traits, resistance genes, and RGAs were also placed on the map, including markers for resistance to Striga gesnerioides races 1 and 3, CPMV, CPSMV, B1CMV, SBMV, Fusarium wilt, and root-knot nematodes. These markers will be useful for the development of tools for marker-assisted selection in cowpea breeding, as well as for subsequent map-based cloning of the various resistance genes. PMID:11908660

Ouédraogo, J T; Gowda, B S; Jean, M; Close, T J; Ehlers, J D; Hall, A E; Gillaspie, A G; Roberts, P A; Ismail, A M; Bruening, G; Gepts, P; Timko, M P; Belzile, F J

2002-02-01

344

Genetic diversity of cultivated flax (Linum usitatissimum L.) germplasm assessed by retrotransposon-based markers.  

PubMed

Retrotransposon segments were characterized and inter-retrotransposon amplified polymorphism (IRAP) markers developed for cultivated flax (Linum usitatissimum L.) and the Linum genus. Over 75 distinct long terminal repeat retrotransposon segments were cloned, the first set for Linum, and specific primers designed for them. IRAP was then used to evaluate genetic diversity among 708 accessions of cultivated flax comprising 143 landraces, 387 varieties, and 178 breeding lines. These included both traditional and modern, oil (86), fiber (351), and combined-use (271) accessions, originating from 36 countries, and 10 wild Linum species. The set of 10 most polymorphic primers yielded 141 reproducible informative data points per accession, with 52% polymorphism and a 0.34 Shannon diversity index. The maximal genetic diversity was detected among wild Linum species (100% IRAP polymorphism and 0.57 Jaccard similarity), while diversity within cultivated germplasm decreased from landraces (58%, 0.63) to breeding lines (48%, 0.85) and cultivars (50%, 0.81). Application of Bayesian methods for clustering resulted in the robust identification of 20 clusters of accessions, which were unstratified according to origin or user type. This indicates an overlap in genetic diversity despite disruptive selection for fiber versus oil types. Nevertheless, eight clusters contained high proportions (70-100%) of commercial cultivars, whereas two clusters were rich (60%) in landraces. These findings provide a basis for better flax germplasm management, core collection establishment, and exploration of diversity in breeding, as well as for exploration of the role of retrotransposons in flax genome dynamics. PMID:21293839

Smýkal, P; Ba?ová-Kerteszová, N; Kalendar, R; Corander, J; Schulman, A H; Pavelek, M

2011-02-04

345

Genetic differentiation induced by spaceflight treatment of Cistanche deserticola and identification of inter-simple sequence repeat markers associated with its medicinal constituent contents  

NASA Astrophysics Data System (ADS)

The dried, fleshy stems of Cistanche deserticola (Orobanchaceae) are popular tonics in Traditional Chinese Medicine (TCM) to treat the inability of kidney in expelling extra fluid in the body, causing fluid retention, and reform reproductive system. However, the wild plants of C. deserticola have become endangered due to habitat downsizing and over-harvesting for its medicinal usages. The present research was carried out for the following purposes: (1) promoting the space-breeding research; (2) providing molecular evidence for agricultural selective breeding; and (3) protecting this endangered herbal medicine and conserving its genetic resources.In this study, plants were cultivated from seeds specifically treated in spaceflight for seven days, and sampled to screen positive mutants and identify ISSR markers associated with their medicinal constituents. As a result, nine out of the 94 ISSR primers were showed high polymorphism, and a total of 118 bands were generated, of which 80 were polymorphic, ranging from 250 to 2600 bp. The spaceflight mutants were found to have lower coefficient of gene differentiation (Gst = 0.0269), and higher gene flow (Nm = 18.0740) than those of the controls (Gst = 0.2067 and Nm = 1.9185). The results demonstrated that most of the genetic variation were harnessed within populations (>97%). The Analysis of Molecular Variance (AMOVA) revealed high genetic variation within populations (88.03%) and low genetic differentiation among regions (-18.83%) and populations (30.79%), respectively. The results also indicated a profound difference between spaceflight condition and that on the earth. The unique vacuum environment of spaceflight was suggested to induce DNA mutation and various variations of C. deserticola. In addition, six particular ISSR markers were identified, cloned and sequenced; one of them, CA41939-934, was found positively correlated with acteoside with correlation coefficient values of 0.264 (P < 0.05). Our work may provide a valuable molecular evidence for establishing conservation strategies and space-breeding research program.

Wu, Y.; Yang, D. Y.; Tu, P. F.; Tian, Y. Z.; Guo, Y. H.; Wang, X. M.; Li, X. B.

2011-02-01

346

Bovine Campylobacter jejuni Strains Differ from Human and Chicken Strains in an Analysis of Certain Molecular Genetic Markers?  

PubMed Central

The association of four new genetic markers with a chicken, bovine, or human host was studied among 645 Campylobacter jejuni isolates. The ?-glutamate transpeptidase gene and dmsA were common in human and chicken isolates but uncommon among bovine isolates. In the t test, bovine isolates differed significantly (P < 0.05) from human and chicken isolates.

Gonzalez, Manuel; Hakkinen, Marjaana; Rautelin, Hilpi; Hanninen, Marja-Liisa

2009-01-01

347

Genetic variation in the endemic and endangered Rosmarinus tomentosus Huber-Morath & Maire (Labiatae) using RAPD markers  

Microsoft Academic Search

Rosmarinus tomentosus Huber-Morath & Maire, an endemic species of southern Spain, is critically endangered as a consequence of habitat destruction by anthropogenic activities. Random amplified polymorphic DNA (RAPD) markers were used for initial evaluation of genetic variation in this species; among zones, among populations (within zones and independently of zones), and among individuals (within populations and zones). The eight primers

Juan Pedro Martín; J Esteban Hernández Bermejo

2000-01-01

348

Simple sequence repeat marker diversity in cassava landraces: genetic diversity and differentiation in an asexually propagated crop  

Microsoft Academic Search

Cassava ( Manihot esculenta) is an allogamous, vegetatively propagated, Neotropical crop that is also widely grown in tropical Africa and Southeast Asia. To elucidate genetic diversity and differentiation in the crop's primary and secondary centers of diversity, and the forces shaping them, SSR marker variation was assessed at 67 loci in 283 accessions of cassava landraces from Africa (Tanzania and

M. A. Fregene; M. Suarez; J. Mkumbira; H. Kulembeka; E. Ndedya; A. Kulaya; S. Mitchel; U. Gullberg; H. Rosling; A. G. O. Dixon; R. Dean; S. Kresovich

2003-01-01

349

Genetic diversity and structure of Ethiopian, Yemen and Brazilian C offea arabica L. accessions using microsatellites markers  

Microsoft Academic Search

Genetic diversity among 115 coffee accessions from the Coffea Germplasm Collection of IAC was assessed using SSR markers. The germplasm represents 73 accessions of Coffea arabica derived from spontaneous and subspontaneous plants in Ethiopia and Eritrea, species center of origin and diversity, 13 commercial\\u000a cultivars of C. arabica developed by the Breeding Program of IAC, 1 accession of C. arabica

Milene Silvestrini; Michele G. Junqueira; Andréa C. Favarin; Oliveiro Guerreiro-Filho; Mirian P. Maluf; Maria B. Silvarolla; Carlos A. Colombo

2007-01-01

350

ASSESSING GENETIC DIVERSITY AND POPULATION STRUCTURE IN A CITRUS GERMPLASM COLLECTION UTILIZING SIMPLE SEQUENCE REPEAT MARKERS (SSRS)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Twenty-four simple sequence repeat (SSR) markers were used to detect molecular polymorphisms among 370 apparently sexually-derived Citrus accessions from the Citrus Variert Collection maintained at the University of California, Riverside. Genetic diversity statistics were calculated for each indivi...

351

Analysis of genetic diversity in early introduced clones of rubber tree (Hevea brasiliensis) using RAPD and microsatellite markers  

Microsoft Academic Search

Genetic analysis in 53 early introduced clones of rubber tree (Hevea brasiliensis) collected from different areas in Southern Thailand was performed using RAPD (Random Amplified Polymorphic DNA) and microsatellite markers. Seven- teen cultivated clones (34 samples) were also included to compare DNA patterns. DNA was isolated from leaf samples using CTAB buffer. One hundred and ninety two 10-base oligonucleotide primers

Korakot Nakkanong; Charassri Nualsri; Sayan Sdoodee

2008-01-01

352

Genetic differentiation and history of populations of the Italian treefrog Hyla intermedia: lack of concordance between mitochondrial and nuclear markers.  

PubMed

The genetic differentiation among 33 populations of the Italian treefrog, Hyla intermedia (Anura: Hylidae), was investigated using both biparentally (23 allozyme loci) and maternally (partial mitochondrial cytochrome b gene) inherited markers. Two main population groups were evidenced by both markers, located north and south of the northern Apennines. However, the pattern of differentiation between these two groups was much less pronounced at allozymes than at mtDNA, leading to gene flow estimates that were 25 times lower at mitochondrial than at nuclear level. Also, the mtDNA divergence between the two groups was particularly marked for two cospecific lineages of anuran amphibians (the P-distance being on average 9.04%), while their average genetic distance at allozymes was comparatively low (D (NEI) = 0.07). This contrasting pattern of nuclear versus mitochondrial genetic variation is discussed in the context of: (1) marker specific selection, (2) secondary contact and sex-biased gene flow and (3) ancestral polymorphism and colonization from north to south. Finally we emphasize how, for population genetic studies, the use of multiple markers having distinct evolutionary properties can help unravel the existence of more complex evolutionary histories. PMID:17061145

Canestrelli, Daniele; Verardi, Andrea; Nascetti, Giuseppe

2006-10-24

353

Markers of genetic susceptibility in human environmental hygiene and toxicology: The role of selected CYP, NAT and GST genes  

Microsoft Academic Search

Inherited genetic traits co-determine the susceptibility of an individual to a toxic chemical. Special emphasis has been put on individual responses to environmental and industrial carcinogens, but other chronic diseases are of increasing interest. Polymorphisms of relevant xenobiotic metabolising enzymes may be used as toxicological susceptibility markers. A growing number of genes encoding enzymes involved in biotransformation of toxicants and

Ricarda Thier; Thomas Brüning; Peter H. Roos; Hans-Peter Rihs; Klaus Golka; Yon Ko; Hermann M. Bolt

2003-01-01

354

Genetic diversity of ‘Candidatus Liberibacter solanacearum’ isolates in the United States and Mexico reveled by simple sequence repeat markers  

Technology Transfer Automated Retrieval System (TEKTRAN)

‘Candidatus Liberibacter solanacearum’ is associated with the Zebra Chip disorder of potatoes. A panel of eight simple sequence repeat (SSR) markers was developed and used to genetically characterize ‘Ca. L. solanacearum’ strains obtained from ZC-affected potato plants in the United States and Mexi...

355

MICROSATELLITE MARKER DEVELOPMENT AND GENETIC VARIATION IN THE TOXIC MARINE DIATOM PSEUDO-NITZSCHIA MULTISERIES (BACILLARIOPHYCEAE)1  

Microsoft Academic Search

The genetic structure of phytoplankton popula- tions is largely unknown. In this study we devel- oped nine polymorphic microsatellite markers for the domoic acid-producing marine diatom Pseudo- nitzschia multiseries (Hasle) Hasle. We then used them in the genotyping of 25 physiologically di- verse field isolates and six of their descendants: 22 field isolates originated from eastern Canadian waters, two from

Katharine M. Evans; Stephen S. Bates; Linda K. Medlin; Paul K. Hayes

2004-01-01

356

Induction, by thymidylate stress, of genetic recombination as evidenced by deletion of a transferred genetic marker in mouse FM3A cells  

SciTech Connect

Studies were made on the genetic consequences of methotrexate-directed thymidylate stress, focusing attention on a human thymidylate synthase gene that was introduced as a heterologous genetic marker into mouse thymidylate synthase-negative mutant cells. Thymidylate stress induced thymidylate synthase-negative segregants with concomitant loss of human thymidylate synthase activity with frequencies 1 to 2 orders of magnitude higher than the uninduced spontaneous level in some but not all transformant lines. Induction of the segregants was suppressed almost completely by cycloheximide and partially by caffeine. Thymidylate stress did not, however, induce mutations, as determined by measuring resistance to ouabain or 6-thioguanine. Thymidylate synthase-negative segregants were also induced by other means such as bromodeoxyuridine treatment and X-ray irradiation. In each of the synthase-negative segregants induced by thymidylate stress, a DNA segment including almost the whole coding region of the transferred human thymidylate synthase gene was deleted in a very specific manner, as shown by Southern blot analysis with a human Alu sequence and a human thymidylate synthase cDNA as probes. In the segregants that emerged spontaneously at low frequency, the entire transferred genetic marker was lost. In the segregants induced by X-ray irradiation, structural alterations of the genetic marker were random. These results show that thymidylate stress is a physiological factor that provokes the instability of this exogenously incorporated DNA in some specific manner and produces nonrandom genetic recombination in mammalian cells.

Ayusawa, D.; Koyama, H.; Shimizu, K.; Kaneda, S.; Takeishi, K.; Seno, T.

1986-10-01

357

Genetic variation in the Solanaceae fruit bearing species lulo and tree tomato revealed by Conserved Ortholog (COSII) markers.  

PubMed

The Lulo or naranjilla (Solanum quitoense Lam.) and the tree tomato or tamarillo (Solanum betaceum Cav. Sendt.) are both Andean tropical fruit species with high nutritional value and the potential for becoming premium products in local and export markets. Herein, we present a report on the genetic characterization of 62 accessions of lulos (n = 32) and tree tomatoes (n = 30) through the use of PCR-based markers developed from single-copy conserved orthologous genes (COSII) in other Solanaceae (Asterid) species. We successfully PCR amplified a set of these markers for lulos (34 out of 46 initially tested) and tree tomatoes (26 out of 41) for molecular studies. Six polymorphic COSII markers were found in lulo with a total of 47 alleles and five polymorphic markers in tree tomato with a total of 39 alleles in the two populations. Further genetic analyses indicated a high population structure (with F(ST) > 0.90), which may be a result of low migration between populations, adaptation to various niches and the number of markers evaluated. We propose COSII markers as sound tools for molecular studies, conservation and the breeding of these two fruit species. PMID:21637482

Enciso-Rodríguez, Felix; Martínez, Rodrigo; Lobo, Mario; Barrero, Luz Stella

2010-06-01

358

Selection for genetic markers in beef cattle reveals complex associations of thyroglobulin and casein1-S1 with carcass and meat traits  

Technology Transfer Automated Retrieval System (TEKTRAN)

Genetic markers in casein (CSN1S1) and thyroglobulin (TG) genes have previously been associated with fat distribution in cattle. Determining the nature of these genetic associations (additive, recessive, or dominant) has been difficult because both markers have small minor allele frequencies in mos...

359

Identification of RFLP and NBS/PK profiling markers for disease resistance loci in genetic maps of oats.  

PubMed

Two of the domains most widely shared among R genes are the nucleotide binding site (NBS) and protein kinase (PK) domains. The present study describes and maps a number of new oat resistance gene analogues (RGAs) with two purposes in mind: (1) to identify genetic regions that contain R genes and (2) to determine whether RGAs can be used as molecular markers for qualitative loci and for QTLs affording resistance to Puccinia coronata. Such genes have been mapped in the diploid A. strigosa × A. wiestii (Asw map) and the hexaploid MN841801-1 × Noble-2 (MN map). Genomic and cDNA NBS-RGA probes from oat, barley and wheat were used to produce RFLPs and to obtain markers by motif-directed profiling based on the NBS (NBS profiling) and PK (PK profiling) domains. The efficiency of primers used in NBS/PK profiling to amplify RGA fragments was assessed by sequencing individual marker bands derived from genomic and cDNA fragments. The positions of 184 markers were identified in the Asw map, while those for 99 were identified in the MN map. Large numbers of NBS and PK profiling markers were found in clusters across different linkage groups, with the PK profiling markers more evenly distributed. The location of markers throughout the genetic maps and the composition of marker clusters indicate that NBS- and PK-based markers cover partly complementary regions of oat genomes. Markers of the different classes obtained were found associated with the two resistance loci, PcA and R-284B-2, mapped on Asw, and with five out of eight QTLs for partial resistance in the MN map. 53 RGA-RFLPs and 187 NBS/PK profiling markers were also mapped on the hexaploid map A. byzantina cv. Kanota × A. sativa cv. Ogle. Significant co-localization was seen between the RGA markers in the KO map and other markers closely linked to resistance loci, such as those for P. coronata and barley yellow dwarf virus (Bydv) that were previously mapped in other segregating populations. PMID:22948438

Sanz, M J; Loarce, Y; Fominaya, A; Vossen, J H; Ferrer, E

2012-09-05

360

New chloroplast microsatellite markers suitable for assessing genetic diversity of Lolium perenne and other related grass species  

PubMed Central

Background and Aims Lolium perenne (perennial ryegrass) is the most important forage grass species of temperate regions. We have previously released the chloroplast genome sequence of L. perenne ‘Cashel’. Here nine chloroplast microsatellite markers are published, which were designed based on knowledge about genetically variable regions within the L. perenne chloroplast genome. These markers were successfully used for characterizing the genetic diversity in Lolium and different grass species. Methods Chloroplast genomes of 14 Poaceae taxa were screened for mononucleotide microsatellite repeat regions and primers designed for their amplification from nine loci. The potential of these markers to assess genetic diversity was evaluated on a set of 16 Irish and 15 European L. perenne ecotypes, nine L. perenne cultivars, other Lolium taxa and other grass species. Key Results All analysed Poaceae chloroplast genomes contained more than 200 mononucleotide repeats (chloroplast simple sequence repeats, cpSSRs) of at least 7 bp in length, concentrated mainly in the large single copy region of the genome. Nucleotide composition varied considerably among subfamilies (with Pooideae biased towards poly A repeats). The nine new markers distinguish L. perenne from all non-Lolium taxa. TeaCpSSR28 was able to distinguish between all Lolium species and Lolium multiflorum due to an elongation of an A8 mononucleotide repeat in L. multiflorum. TeaCpSSR31 detected a considerable degree of microsatellite length variation and single nucleotide polymorphism. TeaCpSSR27 revealed variation within some L. perenne accessions due to a 44-bp indel and was hence readily detected by simple agarose gel electrophoresis. Smaller insertion/deletion events or single nucleotide polymorphisms detected by these new markers could be visualized by polyacrylamide gel electrophoresis or DNA sequencing, respectively. Conclusions The new markers are a valuable tool for plant breeding companies, seed testing agencies and the wider scientific community due to their ability to monitor genetic diversity within breeding pools, to trace maternal inheritance and to distinguish closely related species.

Diekmann, Kerstin; Hodkinson, Trevor R.; Barth, Susanne

2012-01-01

361

Complete sequence of HLA-B27 cDNA identified through the characterization of structural markers unique to the HLA-A, -B, and -C allelic series  

SciTech Connect

Antigen HLA-B27 is a high-risk genetic factor with respect to a group of rheumatoid disorders, especially ankylosing spondylitis. A cDNA library was constructed from an autozygous B-cell line expressing HLA-B27, HLA-Cw1, and the previously cloned HLA-A2 antigen. Clones detected with an HLA probe were isolated and sorted into homology groups by differential hybridization and restriction maps. Nucleotide sequencing allowed the unambiguous assignment of cDNAs to HLA-A, -B, and -C loci. The HLA-B27 mRNA has the structure features and the codon variability typical of an HLA class I transcript but it specifies two uncommon amino acid replacements: a cysteine in position 67 and a serine in position 131. The latter substitution may have functional consequences, because it occurs in a conserved region and at a position invariably occupied by a species-specific arginine in humans and lysine in mice. The availability of the complete sequence of HLA-B27 and of the partial sequence of HLA-Cw1 allows the recognition of locus-specific sequence markers, particularly, but not exclusively, in the transmembrane and cytoplasmic domains.

Szoets, H.; Reithmueller, G.; Weiss, E.; Meo, T.

1986-03-01

362

The estimation of genetic relationships using molecular markers and their efficiency in estimating heritability in natural populations  

PubMed Central

Molecular marker data collected from natural populations allows information on genetic relationships to be established without referencing an exact pedigree. Numerous methods have been developed to exploit the marker data. These fall into two main categories: method of moment estimators and likelihood estimators. Method of moment estimators are essentially unbiased, but utilise weighting schemes that are only optimal if the analysed pair is unrelated. Thus, they differ in their efficiency at estimating parameters for different relationship categories. Likelihood estimators show smaller mean squared errors but are much more biased. Both types of estimator have been used in variance component analysis to estimate heritability. All marker-based heritability estimators require that adequate levels of the true relationship be present in the population of interest and that adequate amounts of informative marker data are available. I review the different approaches to relationship estimation, with particular attention to optimizing the use of this relationship information in subsequent variance component estimation.

Thomas, Stuart C

2005-01-01

363

Identification of Nonpoint Sources of Fecal Pollution in Coastal Waters by Using Host-Specific 16S Ribosomal DNA Genetic Markers from Fecal Anaerobes  

Microsoft Academic Search

We describe a new PCR-based method for distinguishing human and cow fecal contamination in coastal waters without culturing indicator organisms, and we show that the method can be used to track bacterial marker sequences in complex environments. We identified two human-specific genetic markers and five cow-specific genetic markers in fecal samples by amplifying 16S ribosomal DNA (rDNA) fragments from members

ANNE E. BERNHARD; KATHARINE G. FIELD

2000-01-01

364

Analysis of genetic variability in Aristaeomorpha foliacea (crustacea, aristeidae) using DNA-ISSR (Inter Simple Sequence Repeats) markers.  

PubMed

This work reports the first genetic data of Aristaeomorpha foliacea, a marine decapod of high commercial value, from six Mediterranean localities and one new fishing ground in the Mozambique Channel. The use of five Inter Simple Sequence Repeat (ISSR) primers provided 150 polymorphic loci. Average estimates of genetic diversity did not significantly differ among sampled localities, with a mean value of heterozygosity H=0.105±0.015. Analysis of molecular variance (AMOVA) allocated>98% of genetic variability to the within-sample component, displaying values higher than those previously reported in ISSR studies on marine invertebrates. Cluster analyses did not detect geographically or genetically distinct groups. The observed lack of large-scale genetic differentiation is discussed in relation to the high potential for larval dispersal of the species and to features of the marker employed. PMID:21943519

Fernández, Maria Victoria; Maltagliati, Ferruccio; Pannacciulli, Federica G; Roldán, Maria Inés

2011-09-07

365

Integration of novel SSR and gene-based SNP marker loci in the chickpea genetic map and establishment of new anchor points with Medicago truncatula genome  

PubMed Central

This study presents the development and mapping of simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers in chickpea. The mapping population is based on an inter-specific cross between domesticated and non-domesticated genotypes of chickpea (Cicer arietinum ICC 4958 × C. reticulatum PI 489777). This same population has been the focus of previous studies, permitting integration of new and legacy genetic markers into a single genetic map. We report a set of 311 novel SSR markers (designated ICCM—ICRISAT chickpea microsatellite), obtained from an SSR-enriched genomic library of ICC 4958. Screening of these SSR markers on a diverse panel of 48 chickpea accessions provided 147 polymorphic markers with 2–21 alleles and polymorphic information content value 0.04–0.92. Fifty-two of these markers were polymorphic between parental genotypes of the inter-specific population. We also analyzed 233 previously published (H-series) SSR markers that provided another set of 52 polymorphic markers. An additional 71 gene-based SNP markers were developed from transcript sequences that are highly conserved between chickpea and its near relative Medicago truncatula. By using these three approaches, 175 new marker loci along with 407 previously reported marker loci were integrated to yield an improved genetic map of chickpea. The integrated map contains 521 loci organized into eight linkage groups that span 2,602 cM, with an average inter-marker distance of 4.99 cM. Gene-based markers provide anchor points for comparing the genomes of Medicago and chickpea, and reveal extended synteny between these two species. The combined set of genetic markers and their integration into an improved genetic map should facilitate chickpea genetics and breeding, as well as translational studies between chickpea and Medicago. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1265-1) contains supplementary material, which is available to authorized users.

Nayak, Spurthi N.; Zhu, Hongyan; Varghese, Nicy; Datta, Subhojit; Choi, Hong-Kyu; Horres, Ralf; Jungling, Ruth; Singh, Jagbir; Kavi Kishor, P. B.; Sivaramakrishnan, S.; Hoisington, Dave A.; Kahl, Gunter; Winter, Peter; Cook, Douglas R.

2010-01-01

366

Integration of novel SSR and gene-based SNP marker loci in the chickpea genetic map and establishment of new anchor points with Medicago truncatula genome.  

PubMed

This study presents the development and mapping of simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers in chickpea. The mapping population is based on an inter-specific cross between domesticated and non-domesticated genotypes of chickpea (Cicer arietinum ICC 4958 x C. reticulatum PI 489777). This same population has been the focus of previous studies, permitting integration of new and legacy genetic markers into a single genetic map. We report a set of 311 novel SSR markers (designated ICCM-ICRISAT chickpea microsatellite), obtained from an SSR-enriched genomic library of ICC 4958. Screening of these SSR markers on a diverse panel of 48 chickpea accessions provided 147 polymorphic markers with 2-21 alleles and polymorphic information content value 0.04-0.92. Fifty-two of these markers were polymorphic between parental genotypes of the inter-specific population. We also analyzed 233 previously published (H-series) SSR markers that provided another set of 52 polymorphic markers. An additional 71 gene-based SNP markers were developed from transcript sequences that are highly conserved between chickpea and its near relative Medicago truncatula. By using these three approaches, 175 new marker loci along with 407 previously reported marker loci were integrated to yield an improved genetic map of chickpea. The integrated map contains 521 loci organized into eight linkage groups that span 2,602 cM, with an average inter-marker distance of 4.99 cM. Gene-based markers provide anchor points for comparing the genomes of Medicago and chickpea, and reveal extended synteny between these two species. The combined set of genetic markers and their integration into an improved genetic map should facilitate chickpea genetics and breeding, as well as translational studies between chickpea and Medicago. PMID:20098978

Nayak, Spurthi N; Zhu, Hongyan; Varghese, Nicy; Datta, Subhojit; Choi, Hong-Kyu; Horres, Ralf; Jüngling, Ruth; Singh, Jagbir; Kishor, P B Kavi; Sivaramakrishnan, S; Hoisington, Dave A; Kahl, Günter; Winter, Peter; Cook, Douglas R; Varshney, Rajeev K

2010-01-23

367

Common Genetic Contributions to Depressive Symptoms and Inflammatory Markers in Middle-Aged Men: The Twins Heart Study  

PubMed Central

Objective To examine the extent to which a common genetic pathway is also involved in the relationship between depressive symptoms, in the absence of major depressive disorder (MDD), and inflammation. Recent data suggested that MDD and inflammation share common genes. Methods We recruited 188 male twins from the Vietnam Era Twin Registry who were free of symptomatic coronary artery disease and MDD, with mean ± standard deviation (SD) age of 55 ± 2.75 years, including 54 monozygotic and 40 dizygotic twin pairs. These pairs were assessed for two inflammatory markers, interleukin (IL)-6 and C-reactive protein (CRP). Current depressive symptoms were measured with the Beck Depression Inventory-II. Generalized estimating equations were used to examine the phenotypic association between depression and inflammatory markers. Biometrical genetic modeling was performed to estimate the genetic and environmental contributions to this association. Results An association was observed between severity of current depressive symptoms and increased levels of inflammatory markers (p < .001 for IL-6 and p = .005 for CRP). After adjustment for other factors, the association was slightly attenuated but remained statistically significant for IL-6 (p = .002). The heritability of IL-6, CRP, and depressive symptoms were estimated as 0.37, 0.65, and 0.48, respectively. Genetic modeling found a significant genetic correlation between IL-6 and depressive symptoms (rG = 0.22, p = .046), indicating that about 66% of the covariance between them can be explained by shared genetic influences. Conclusions Current depressive symptoms are significantly correlated with inflammatory markers. This covariation is due, in large part, to genes that are common to depressive symptoms and inflammation.

Su, Shaoyong; Miller, Andrew H.; Snieder, Harold; Bremner, J. Douglas; Ritchie, James; Maisano, Carisa; Jones, Linda; Murrah, Nancy V.; Goldberg, Jack; Vaccarino, Viola

2010-01-01

368

Animal models of physiologic markers of male reproduction: genetically defined infertile mice  

SciTech Connect

The present report focuses on novel animal models of male infertility: genetically defined mice bearing single-gene mutations that induce infertility. The primary goal of the investigations was to identify the reproductive defects in these mutant mice. The phenotypic effects of the gene mutations were deciphered by comparing the mutant mice to their normal siblings. Initially testicular steroidogenesis and spermatogenesis were investigated. The physiologic markers for testicular steroidogenesis were steroid secretion by testes perifused in vitro, seminal vesicle weight, and Leydig cell histology. Spermatogenesis was evaluated by the enumeration of homogenization-resistant sperm/spermatids in testes and by morphometric analyses of germ cells in the seminiferous epithelium. If testicular function appeared normal, the authors investigated the sexual behavior of the mice. The parameters of male sexual behavior that were quantified included mount patency, mount frequency, intromission latency, thrusts per intromission, ejaculation latency, and ejaculation duration. Females of pairs breeding under normal circumstances were monitored for the presence of vaginal plugs and pregnancies. The patency of the ejaculatory process was determined by quantifying sperm in the female reproductive tract after sexual behavior tests. Sperm function was studied by quantitatively determining sperm motility during videomicroscopic observation. Also, the ability of epididymal sperm to function within the uterine environment was analyzed by determining sperm capacity to initiate pregnancy after artificial insemination. Together, the experimental results permitted the grouping of the gene mutations into three general categories. They propose that the same biological markers used in the reported studies can be implemented in the assessment of the impact that environmental toxins may have on male reproduction.

Chubb, C.

1987-10-01

369

Animal models of physiologic markers of male reproduction: genetically defined infertile mice.  

PubMed Central

The present report focuses on novel animal models of male infertility: genetically defined mice bearing single-gene mutations that induce infertility. The primary goal of our investigations was to identify the reproductive defects in these mutant mice. The phenotypic effects of the gene mutations were deciphered by comparing the mutant mice to their normal siblings. Initially testicular steroidogenesis and spermatogenesis were investigated. The physiologic markers for testicular steroidogenesis were steroid secretion by testes perifused in vitro, seminal vesicle weight, and Leydig cell histology. Spermatogenesis was evaluated by the enumeration of homogenization-resistant sperm/spermatids in testes and by morphometric analyses of germ cells in the seminiferous epithelium. If testicular function appeared normal, we investigated the sexual behavior of the mice. The parameters of male sexual behavior that were quantified included mount patency, mount frequency, intromission latency, thrusts per intromission, ejaculation latency, and ejaculation duration. Females of pairs breeding under normal circumstances were monitored for the presence of vaginal plugs and pregnancies. The patency of the ejaculatory process was determined by quantifying sperm in the female reproductive tract after sexual behavior tests. Sperm function was studied by quantitatively determining sperm motility during videomicroscopic observation. Also, the ability of epididymal sperm to function within the uterine environment was analyzed by determining sperm capacity to initiate pregnancy after artificial insemination. Together, the experimental results permitted the grouping of the gene mutations into three general categories. We propose that the same biological markers used in the reported studies can be implemented in the assessment of the impact that environmental toxins may have on male reproduction.

Chubb, C

1987-01-01

370

Population genetic data for 17 Y STR markers from Benghazi (East Libya).  

PubMed

The seventeen Y-STR loci included in the AmpF?STR(®) Yfiler™ PCR Amplification kit (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385a/b, DYS438, DYS439, DYS437, DYS448, DYS458, DYS456, DYS635, and Y-GATA-H4) were used to type a sample population of 238 males from eastern Libya (Benghazi region). Of 238 observed haplotypes, 214 were unique (90%) and 24 (10%) were found more than once. The 17 loci gave a discriminating power of 0.999. DYS458 showed the highest diversity as a single-locus marker (0.73). Allelic frequencies and gene diversities for each Y-STR locus were determined. The high haplotype diversity and discrimination capacity (0.996) demonstrate the utility of these loci for human identification in forensic applications. Comparative analysis with Y-STR datasets of relevant populations and submission of the haplotypes to the Y-STR Haplotype Reference Database (YHRD) was undertaken. PMID:21640679

Elmrghni, Samir; Coulson-Thomas, Yvette M; Kaddura, Mahmoud; Dixon, Ron A; Williams, D Ross

2011-06-02

371

Assessment of cattle genetic introgression into domestic yak populations using mitochondrial and microsatellite DNA markers  

PubMed Central

Hybridization between yak Poephagus grunniens and taurine Bos taurus or indicine B. indicus cattle has been widely practiced throughout the yak geographical range, and gene flow is expected to have occurred between these species. To assess the impact of cattle admixture on domestic yak, we examined 1076 domestic yak from 29 populations collected in China, Bhutan, Nepal, India, Pakistan, Kyrgyzstan, Mongolia and Russia using mitochondrial DNA and 17 autosomal microsatellite loci. A cattle diagnostic marker-based analysis reveals cattle-specific mtDNA and/or autosomal microsatellite allele introgression in 127 yak individuals from 22 populations. The mean level of cattle admixture across the populations, calculated using allelic information at 17 autosomal microsatellite loci, remains relatively low (mYcattle = 2.66 ± 0.53% and Qcattle = 0.69 ± 2.58%), although it varies a lot across populations as well as among individuals within population. Although the level of cattle admixture shows a clear geographical structure, with higher levels of admixture in the Qinghai-Tibetan Plateau and Mongolian and Russian regions, and lower levels in the Himalayan and Pamir Plateau region, our results indicate that the level of cattle admixture is not significantly correlated with the altitude across geographical regions as well as within geographical region. Although yak-cattle hybridization is primarily driven to produce F1 hybrids, our results show that the subsequent gene flow between yak and cattle took place and has affected contemporary genetic make-up of domestic yak. To protect yak genetic integrity, hybridization between yak and cattle should be tightly controlled.

Qi, X B; Jianlin, H; Wang, G; Rege, J E O; Hanotte, O

2010-01-01

372

Genetic analysis of a local population of Oryza glumaepatula using SSR markers: implications for management and conservation programs.  

PubMed

Knowledge of natural diversity and population structures of wild species, which might be related to cultivated species, is fundamental for conservation and breeding purposes. In this study, a genetic characterization of a large population of Oryza glumaepatula, occurring in a 10 km(2) area located at Tamengo Basin (Paraguay River, Brazil), was performed using SSR markers. This population is annually dragged from the river to permit navigation; one goal of this study was to examine the impact of this removal on genetic variability. From 18 polymorphic SSR markers, a total of 190 alleles were detected in a sample of 126 individuals, with an average of 10.3 alleles/locus, and a H(e) of 0.67. The five QTL-related markers showed an average H(e) value of 0.56, while the remaining 13 markers detected an average estimate of 0.70. An apparent outcrossing rate of 30%, a high proportion of alleles at low frequencies (56%), and the presence of exclusive alleles (9.5%) were found, with strong evidence of the establishment of individuals from different populations upstream in the Paraguay River. For conservation purposes, the river drag has no effect on the population. However, periodical seed collection from the Corumbá population can preserve part of the genetic variability present in upstream populations reducing the need for upriver collecting expeditions. PMID:19636802

de Campos Vaz, Ana Rosa; de Oliveira Borba, Tereza Cristina; Brondani, Claudio; Rangel, Paulo Hideo Nakano; de Oliveira Camargo, Graziela Silvia; de Campos Telles, Mariana Pires; Filho, José Alexandre Felizola Diniz; Brondani, Rosana Pereira Vianello

2009-07-28

373

Use of a genetically-engineered Escherichia coli strain as a sample process control for quantification of the host-specific bacterial genetic markers.  

PubMed

Quantitative PCR (qPCR) assays targeting the host-specific Bacteroides-Prevotella 16S rRNA genetic markers have been proposed as one of the promising approaches to identify the source of fecal contamination in environmental waters. One of the concerns of qPCR assays to environmental samples is the reliability of quantified values, since DNA extraction followed by qPCR assays are usually performed without appropriate sample process control (SPC) and internal amplification controls (IACs). To check the errors in sample processing and improve the reliability of qPCR results, it is essential to evaluate the DNA recovery efficiency and PCR amplification efficiency of the target genetic markers and correct the measurement results. In this study, we constructed a genetically-engineered Escherichia coli K12 strain (designated as strain MG1655 ?lac::kan) as sample process control and evaluated the applicability to environmental water samples. The recovery efficiency of the SPC strain MG1655 ?lac::kan was similar to that of Bacteroides fragilis JCM 11019, when DNA were extracted from water samples spiked with the two bacteria. Furthermore, the SPC was included in the qPCR assays with propidium monoazide (PMA) treatment, which can exclude the genetic markers from dead cells. No significant DNA loss was observed in the PMA treatment. The inclusion of both the SPC (strain MG1655 ?lac::kan) and IAC in qPCR assays with PMA treatment gave the assurance of reliable results of host-specific Bacteroides-Prevotella 16S rRNA genetic markers in environmental water samples. PMID:23989919

Kobayashi, Ayano; Sano, Daisuke; Taniuchi, Asami; Ishii, Satoshi; Okabe, Satoshi

2013-08-29

374

Phylogenetic relationships and genetic diversity of the USDA Vigna germplasm collection revealed by gene-derived markers and sequencing.  

PubMed

Phylogenetic relationships in the USDA Vigna germplasm collection are somewhat unclear and their genetic diversity has not been measured empirically. To reveal interspecific phylogenetic relationships and assess their genetic diversity, 48 accessions representing 12 Vigna species were selected, and 30 gene-derived markers from legumes were employed. Some high-quality amplicons were sequenced. Indels (insertion/deletions) were discovered from the sequence alignments that were specific identifiers for some Vigna species. With regard to revealing polymorphisms, intron-spanning markers were more effective than exon-derived markers. These gene-derived markers were more successful in revealing interspecific polymorphisms than intraspecific polymorphisms at both the DNA fragment and sequence levels. Two different dendrograms were generated from DNA fragment data and sequence data, respectively. The results from these two dendrograms supported each other and showed similar phylogenetic relationships among the Vigna species investigated. The accessions clustered into four main groups and 13 subgroups. Each subgroup represents a subgenus or a species. Phylogenetic analysis revealed that an accession might be misclassified in our collection. The putative misclassified accession was further supported by seed morphology. Limited intraspecific genetic diversity was revealed by these gene-derived markers and/or sequences. The USDA Vigna germplasm collection currently consists of multiple species with many accessions further classified into specific subspecies, but very few subspecies of the total subspecies available exist within the collection. Based on our results, more attention should be paid to the subspecies, wild forms and/or botanical varieties for future curation in order to expand the genetic diversity of Vigna germplasm in the USDA collection. PMID:19123965

Wang, Ming Li; Barkley, Noelle A; Gillaspie, Graves A; Pederson, Gary A

2008-12-01

375

Genetic variants and environmental factors associated with hormonal markers of ovarian reserve in Caucasian and African American women  

PubMed Central

BACKGROUND The ovarian reserve (number and quality of oocytes) is correlated with reproductive potential as well as somatic health, and is likely to have multiple genetic and environmental determinants. Several reproductive hormones are closely linked with the oocyte pool and thus can serve as surrogate markers of ovarian reserve. However, we know little about the underlying genes or genetic variants. METHODS We analyzed genetic variants across the genome associated with two hormonal markers of ovarian reserve, FSH and anti-Mullerian hormone, in a reproductively normal population of Caucasian (n = 232) and African American (n = 200) women, aged 25–45 years. We also examined the effects of environmental or lifestyle factors on ovarian reserve phenotypes. RESULTS We identified one variant approaching genome-wide significance (rs6543833; P= 8.07 × 10?8) and several nominal variants nearby and within the myeloid-associated differentiation marker-like (MYADML) gene, that were associated with FSH levels in African American women; these were validated in Caucasian women. We also discovered effects of smoking and oral contraceptive use on ovarian reserve phenotypes, with alterations in several reproductive hormones. CONCLUSIONS This work is the largest study on ovarian reserve in women of reproductive age and is the only genome-wide study on ovarian reserve markers. The genes containing or near the identified variants have no known roles in ovarian biology and represent interesting candidate genes for future investigations. The discovery of genetic markers may lead to better long-range predictions of declining ovarian function, with implications for reproductive and somatic health.

Schuh-Huerta, Sonya M.; Johnson, Nicholas A.; Rosen, Mitchell P.; Sternfeld, Barbara; Cedars, Marcelle I.; Reijo Pera, Renee A.

2012-01-01

376

Spectroscopic detection of fluorescent protein marker gene activity in genetically modified plants  

NASA Astrophysics Data System (ADS)

This work focuses on developing a portable fibre optic fluorescence analyser for rapid identification of genetically modified plants tagged with a fluorescent marker gene. Independent transgenic tobacco plant lines expressing the enhanced green fluorescence protein (EGFP) gene were regenerated following Agrobacterium-mediated gene transfer. Molecular characterisation of these plant lines was carried out at the DNA level by PCR screening to confirm their transgenic status. Conventional transgene expression analysis was then carried out at the RNA level by RT-PCR and at the protein level by Western blotting using anti-GFP rabbit antiserum. The amount of plant-expressed EGFP on a Western blot was quantified against known amounts of purified EGFP by scanning densitometry. The expression level of EGFP in transformed plants was found to range from 0.1 - 0.6% of total extractable protein. A comparison between conventional western analysis of transformants and direct spectroscopic quantification using the fibre optic fluorescence analyser was made. The results showed that spectroscopic measurements of fluorescence emission from strong EGFP expressors correlated positively with Western blot data. However, the fluorescence analyser was also able to identify weakly expressing plant transformants below the detection limit of colorimetric Western blotting.

Liew, O. W.; Chong, Jenny P. C.; Asundi, Anand K.

2005-04-01

377

Utility of genetic markers and morphology for species discrimination within the order Tintinnida (Ciliophora, Spirotrichea).  

PubMed

We evaluated the small- and large-subunit rDNA (SSU and LSU, respectively) for their ability to discriminate morphospecies of tintinnid ciliates. Multiple individuals from 29 morphospecies were identified according to microscopically-observed characteristics of the lorica, and then sequenced for both loci (21 new species for SSU and all of them new for LSU). Sequences from public databases were included in our analyses, and two hypervariable SSU regions (V4 and V9) were separately examined. Of the four regions, LSU is the most useful as a potential barcoding tool. It showed a gap in distances within and between species, and discriminated the maximum number of phylotypes (86% at 1% cut-off). SSU and V4 were less consistent, sometimes lumping together very distinctive morphospecies, even at the 1% level of sequence divergence. V9 was the least reliable marker in delimitating morphospecies. The agreement in sequences and morphology suggests that the lorica is useful for species discrimination, even in agglomerated forms. However, the observation of both genetically constant yet polymorphic groups of species, as well as similar morphospecies with divergent sequences, indicates that previous taxonomic schemes are complementary to the emerging molecular database. PMID:22264493

Santoferrara, Luciana F; McManus, George B; Alder, Viviana A

2012-01-20

378

Molecular typing of, and distribution of genetic markers among, Burkholderia cepacia complex isolates from Brazil.  

PubMed

PCR tests were used to assign genomovar status to 39 non-cystic fibrosis (non-CF) and 11 CF Burkholderia cepacia complex isolates from patients in hospitals in Recife, Brazil. Non-CF isolates were assigned to genomovar IIIA (71.8%), genomovar I (15.4%), B. vietnamiensis (7.7%), and B. multivorans (5.1%). CF isolates were assigned to genomovar IIIA (18.2%), B. vietnamiensis (18.2%), and genomovar I (9.1%). Six CF isolates sharing recA PCR-restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD) patterns could not be assigned to a genomovar. 16S rDNA sequence obtained from these isolates indicated a closest relationship to B. anthina, but the recA sequence was equally divergent from several genomovars. PCR screening indicated the presence of cblA in only two isolates, whereas the B. cepacia epidemic strain marker was found in 22 of 28 genomovar IIIA isolates. A type III secretion gene was detected in all but genomovar I isolates. RAPD and PCR-RFLP assays, targeting both recA and fliC, indicated a large amount of genetic variability among the isolates, with many novel patterns being observed. Nine genomovar IIIA isolates from different non-CF patients and clinical sources had identical genotypes, indicating the presence of a common clone. PMID:12958239

Detsika, Maria G; Corkill, John E; Magalhães, Marcelo; Glendinning, Kerry J; Hart, C Anthony; Winstanley, Craig

2003-09-01

379

Molecular Typing of, and Distribution of Genetic Markers among, Burkholderia cepacia Complex Isolates from Brazil  

PubMed Central

PCR tests were used to assign genomovar status to 39 non-cystic fibrosis (non-CF) and 11 CF Burkholderia cepacia complex isolates from patients in hospitals in Recife, Brazil. Non-CF isolates were assigned to genomovar IIIA (71.8%), genomovar I (15.4%), B. vietnamiensis (7.7%), and B. multivorans (5.1%). CF isolates were assigned to genomovar IIIA (18.2%), B. vietnamiensis (18.2%), and genomovar I (9.1%). Six CF isolates sharing recA PCR-restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD) patterns could not be assigned to a genomovar. 16S rDNA sequence obtained from these isolates indicated a closest relationship to B. anthina, but the recA sequence was equally divergent from several genomovars. PCR screening indicated the presence of cblA in only two isolates, whereas the B. cepacia epidemic strain marker was found in 22 of 28 genomovar IIIA isolates. A type III secretion gene was detected in all but genomovar I isolates. RAPD and PCR-RFLP assays, targeting both recA and fliC, indicated a large amount of genetic variability among the isolates, with many novel patterns being observed. Nine genomovar IIIA isolates from different non-CF patients and clinical sources had identical genotypes, indicating the presence of a common clone.

Detsika, Maria G.; Corkill, John E.; Magalhaes, Marcelo; Glendinning, Kerry J.; Hart, C. Anthony; Winstanley, Craig

2003-01-01

380

Bipodal PEGylated alkanethiol for the enhanced electrochemical detection of genetic markers involved in breast cancer.  

PubMed

Extensive research efforts continue to be invested in the development of low-density electrochemical DNA sensor arrays for application in theranostics and pharmacogenomics. Rapid and low-cost technologies are thus required for genosensor arrays to impact on current medical practice, with sensors clearly being required to detect their targets with high sensitivity and specificity, whilst resisting biofouling and avoiding interfering signals from the sample matrix. We report on the performance of three polyethylene glycol (PEG) co-immobilisation strategies used in the preparation of DNA sensors, using the detection of the breast cancer marker oestrogen receptor-? as a model system. PEGylated DNA capture probes for oestrogen receptor-? were co-immobilised in the presence of either a PEG alkanethiol, a mixture of PEG alkanethiol and mercaptohexanol or a bipodal aromatic PEG alkanethiol. Electrochemical impedance spectroscopy and pulsed amperometry were employed to characterise the prepared surface and sensitivity of the sensor. A surface plasmon resonance study was additionally carried out to confirm the results obtained electrochemically. Finally, the best co-immobilisation system, consisting of the co-assembly of oestrogen receptor-? capture probes and bipodal aromatic PEG alkanethiol in a ratio of 1:100, was used for the electrochemical analysis of a PCR product resulting from the amplification of the genetic material extracted from 20 MCF7 cells. This novel co-immobilisation system exhibited both high electrochemical sensitivity and resistance to fouling believed to results from an enhanced electron permeability and surface hydrophilicity. PMID:20729066

Henry, O Y F; Sanchez, J Lluis Acero; O'Sullivan, C K

2010-08-07

381

Estimation of Pairwise Identity by Descent From Dense Genetic Marker Data in a Population Sample of Haplotypes  

PubMed Central

I present a new approach for calculating probabilities of identity by descent for pairs of haplotypes. The approach is based on a joint hidden Markov model for haplotype frequencies and identity by descent (IBD). This model allows for linkage disequilibrium, and the method can be applied to very dense marker data. The method has high power for detecting IBD tracts of genetic length of 1 cM, with the use of sufficiently dense markers. This enables detection of pairwise IBD between haplotypes from individuals whose most recent common ancestor lived up to 50 generations ago.

Browning, Sharon R.

2008-01-01

382

Long-term selection strategies for complex traits using high-density genetic markers.  

PubMed

Selection of animals for breeding ranked on estimated breeding value maximizes genetic gain in the next generation but does not necessarily maximize long-term response. An alternative method, as practiced by plant breeders, is to build a desired genotype by selection on specific loci. Maximal long-term response in animal breeding requires selection on estimated breeding values with constraints on coancestry. In this paper, we compared long-term genetic response using either a genotype building or a genomic estimated breeding value (GEBV) strategy for the Australian Selection Index (ASI), a measure of profit. First, we used real marker effects from the Australian Dairy Herd Improvement Scheme to estimate breeding values for chromosome segments (approximately 25 cM long) for 2,650 Holstein bulls. Second, we selected 16 animals to be founders for a simulated breeding program where, between them, founders contain the best possible combination of 2 segments from 2 animals at each position in the genome. Third, we mated founder animals and their descendants over 30 generations with 2 breeding objectives: (1) to create a population with the "ideal genotype," where the best 2 segments from the founders segregate at each position, or (2) obtain the highest possible response in ASI with coancestry lower than that achieved under breeding objective 1. Results show that genotype building achieved the ideal genotype for breeding objective 1 and obtained a large gain in ASI over the current population (+A$864.99). However, selection on overall GEBV had greater short-term response and almost as much long-term gain (+A$820.42). When coancestry was lowered under breeding objective 2, selection on overall GEBV achieved a higher response in ASI than the genotype building strategy. Selection on overall GEBV seems more flexible in its selection decisions and was therefore better able to precisely control coancestry while maximizing ASI. We conclude that selection on overall GEBV while minimizing average coancestry is the more practical strategy for dairy cattle where selection is for highly polygenic traits, the reproductive rate is relatively low, and there is low tolerance of coancestry. The outcome may be different for traits controlled by few loci of relatively large effects or for different species. In contrast to other simulations, our results indicate that response to selection on overall GEBV may continue for several generations. This is because long-term genetic change in complex traits requires favorable changes to allele frequencies for many loci located throughout the genome. PMID:22818479

Kemper, K E; Bowman, P J; Pryce, J E; Hayes, B J; Goddard, M E

2012-08-01

383

Sperm analyses, genetic counselling and therapy in an infertile carrier of a supernumerary marker chromosome 15  

Microsoft Academic Search

Purpose: A supernumerary marker chromosome (SMC) was analysed after lymphocyte culture of a patient with oligoasthenoteratozoospermia (OAT) before ICSI treatment. Material and methods: By additional molecular cytogenetic investigations the marker could be identified as a heterochromatic derivate of chromosome 15 (karyotype: 47,XY,+der(15)). Results: Sperm analyses by interphase FISH showed a normal monosomy 15 in 82% and an additional marker in

Paetzold U; Schwanitz G; Schubert R; Ven K; Montag M

2006-01-01

384

[Genetic diversity of Dactylis glomerata germplasm resources detected by Inter-simple Sequence Repeats (ISSRS) molecular markers].  

PubMed

Inter-simple Sequence Repeat (ISSR) molecular markers were used to detect the genetic diversity among 50 materials of Dactylis glomerata collected from China and other countries. Twelve primers produced 101 polymorphic bands, averaged 8.41 bands each primer pair. The average percentage of polymorpgic bands was 86.3.8%, and the range of GS (define) was 0.6116-0.9290, indicating a rich genetic diversity of D. glomerata. Based on the cluster and principal component analyses on the genetic characteristics, D. glomerata could be divided into 5 groups according to the nearest phylogenetic relationship. In most cases, accessions from the same continent were classified into the same group, the accessions from China and the United States belong to the different groups, respectively, indicating the geographical distribution of genetic diversity of D. glomerata. The present paper also discussed collection and conservation of germplasm resources in D. glomerata. PMID:16963418

Zeng, Bing; Zhang, Xin-Quan; Fan, Yan; Lan, Ying; Ma, Xiao; Peng, Yan; Liu, Wei

2006-09-01

385

spa Typing Method for Discriminating among Staphylococcus aureus Isolates: Implications for Use of a Single Marker To Detect Genetic Micro and Macrovariation  

Microsoft Academic Search

Strain typing of microbial pathogens has two major aims: (i) to index genetic microvariation for use in outbreak investigations and (ii) to index genetic macrovariation for use in phylogenetic and population-based analyses. Until now, there has been no clear indication that one genetic marker can efficiently be used for both purposes. Previously, we had shown that DNA sequence analysis of

Larry Koreen; Srinivas V. Ramaswamy; Edward A. Graviss; Steven Naidich; James M. Musser; Barry N. Kreiswirth

2004-01-01

386

Mechanisms and Consequences of Small Supernumerary Marker Chromosomes: From Barbara McClintock to Modern Genetic-Counseling Issues  

PubMed Central

Supernumerary marker chromosomes (SMCs) are common, but their molecular content and mechanism of origin are often not precisely characterized. We analyzed all centromere regions to identify the junction between the unique chromosome arm and the pericentromeric repeats. A molecular-ruler clone panel for each chromosome arm was developed and used for the design of a custom oligonucleotide array. Of 27 nonsatellited SMCs analyzed by array comparative genomic hybridization (aCGH) and/or fluorescence in situ hybridization (FISH), seven (approximately 26%) were shown to be unique sequence negative. Of the 20 unique-sequence-positive SMCs, the average unique DNA content was approximately 6.5 Mb (range 0.3–22.2 Mb) and 33 known genes (range 0–149). Of the 14 informative nonacrocentric SMCs, five (approximately 36%) contained unique DNA from both the p and q arms, whereas nine (approximately 64%) contained unique DNA from only one arm. The latter cases are consistent with ring-chromosome formation by centromere misdivision, as first described by McClintock in maize. In one case, a r(4) containing approximately 4.4 Mb of unique DNA from 4p was also present in the proband's mother. However, FISH revealed a cryptic deletion in one chromosome 4 and reduced alpha satellite in the del(4) and r(4), indicating that the mother was a balanced ring and deletion carrier. Our data, and recent reports in the literature, suggest that this “McClintock mechanism” of small-ring formation might be the predominant mechanism of origin. Comprehensive analysis of SMCs by aCGH and FISH can distinguish unique-negative from unique-positive cases, determine the precise gene content, and provide information on mechanism of origin, inheritance, and recurrence risk.

Baldwin, Erin L.; May, Lorraine F.; Justice, April N.; Martin, Christa L.; Ledbetter, David H.

2008-01-01

387

New Microsatellite Markers for Examining Genetic Variation in Peripheral and Core Populations of the Coastal Giant Salamander (Dicamptodon tenebrosus)  

PubMed Central

The Coastal Giant Salamander (Dicamptodon tenebrosus) is classified as threatened at the northern periphery of its range in British Columbia (BC), Canada, primarily due to forestry practices and habitat fragmentation. Characterising dispersal behaviour and population connectivity is therefore a priority for this region, while genetic differentiation in core versus peripheral locations remains unstudied in this wide-ranging species. We present seven new polymorphic microsatellite markers for use in population genetic analyses of D. tenebrosus. We examine locus characteristics and genetic variation in 12 streams at the species' northern range limit in BC, and within two regions representing sub-peripheral (North Cascades) and core localities (South Cascades) in Washington State, United States. In BC, the number of alleles per locus ranged from 2–5 and observed heterozygosity ranged from 0.044–0.825. Genetic differentiation was highest between BC and the South Cascades, and intermediate between BC and the North Cascades. Across loci, mean allelic richness was similar across regions, while private allelic richness was highest in the core locality (corrected for sample size). These new microsatellite loci will be a valuable addition to existing markers for detailed landscape and population genetic analyses of D. tenebrosus across its range.

Dudaniec, Rachael Y.; Storfer, Andrew; Spear, Stephen F.; Richardson, John S.

2010-01-01

388

New microsatellite markers for examining genetic variation in peripheral and core populations of the Coastal Giant Salamander (Dicamptodon tenebrosus).  

PubMed

The Coastal Giant Salamander (Dicamptodon tenebrosus) is classified as threatened at the northern periphery of its range in British Columbia (BC), Canada, primarily due to forestry practices and habitat fragmentation. Characterising dispersal behaviour and population connectivity is therefore a priority for this region, while genetic differentiation in core versus peripheral locations remains unstudied in this wide-ranging species. We present seven new polymorphic microsatellite markers for use in population genetic analyses of D. tenebrosus. We examine locus characteristics and genetic variation in 12 streams at the species' northern range limit in BC, and within two regions representing sub-peripheral (North Cascades) and core localities (South Cascades) in Washington State, United States. In BC, the number of alleles per locus ranged from 2-5 and observed heterozygosity ranged from 0.044-0.825. Genetic differentiation was highest between BC and the South Cascades, and intermediate between BC and the North Cascades. A